More than 60 people are believed to have been killed, with up to 180 injured in a bomb blast that decimated a busy market in a Shia Muslim quarter of the Pakistani city of Quetta on Saturday.

Authorities said the attack is believed to have been carried out by Sunni Muslim extremists who regularly target Pakistan's estimated 20 million Shias, according to AP.

Wazir Khan Nasir, deputy inspector general of police in Quetta, told: "The explosion was caused by an improvised explosive device fitted to a motorcyle. This is a continuation of terrorism against Shias."

market bomb

Smoke rises from the site of a bomb blast in a market in Quetta, Pakistan

He said the bomb was detonated by remote control and officers are believed to be investigating whether the bomb was planted in a rickshaw.

Many of the victims were women and their children, shopping for the evening meal. The wounded have been take to three different hospitals.

Shiite protesters have demanded action from authorities, and tighter protection. They blocked roads, burnt tyres and threw stones at official vehicles. Police have since cordoned off the area.

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  • A supporter of Pakistani cleric Tahir-ul Qadri poses with a victory sign at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • A supporter of Pakistani cleric Tahir-ul Qadri waves the national flag at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri gather at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Pakistani cleric Tahir-ul Qadri addresses his supporters from his makeshift room at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri chant slogans at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri chant slogans at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • A supporter of Pakistani cleric Tahir-ul Qadri holds a placard at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri gather inthe rain at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri gather at a protest rally in Islamabad on January 17, 2013. Pakistani ministers held talks with a cleric leading a mass protest in Islamabad in an attempt to avert a political crisis and end a demonstration that has heaped pressure on the fragile government. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani moderate preacher Tahir-ul Qadri gather on the fourth day of a protest rally in Islamabad on January 17, 2013. Pakistan's President intervened to stop authorities from using force against protesters who are calling for parliament to be dissolved in Islamabad's largest political rally in years. (ASIF HASSAN/AFP/Getty Images)

  • A supporter of Pakistani moderate preacher Tahir-ul Qadri waves the national flag on the fourth day of a protest rally in Islamabad on January 17, 2013. Pakistan's President intervened to stop authorities from using force against protesters who are calling for parliament to be dissolved in Islamabad's largest political rally in years. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri gesture the victory symbol during a protest rally in Islamabad on January 17, 2013. A populist Pakistani cleric calling for electoral reforms announced that a mass sit-in of tens of thousands of people camped outside parliament in Islamabad would end January 17. (FAROOQ NAEEM/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri gather in the rain during a protest rally in Islamabad on January 17, 2013. A populist Pakistani cleric calling for electoral reforms announced that a mass sit-in of tens of thousands of people camped outside parliament in Islamabad would end January 17. (FAROOQ NAEEM/AFP/Getty Images)

  • A supporter of Pakistani cleric Tahir-ul Qadri wears a plastic bag in the rain during a protest rally in Islamabad on January 17, 2013. A populist Pakistani cleric calling for electoral reforms announced that a mass sit-in of tens of thousands of people camped outside parliament in Islamabad would end January 17. (FAROOQ NAEEM/AFP/Getty Images)

  • A supporter of Pakistani cleric Tahir-ul Qadri enjoys the rain at a protest rally in Islamabad on January 17, 2013. A populist Pakistani cleric calling for electoral reforms announced that a mass sit-in of tens of thousands of people camped outside parliament in Islamabad would end January 17. (FAROOQ NAEEM/AFP/Getty Images)

  • Female supporters of moderate preacher Tahir-ul Qadri stand guard to protect sleeping women taking part in the fourth day of protests in Islamabad early on January 17, 2013. Pakistan's president on January 16 intervened to stop authorities from using force against protesters who are calling for parliament to be dissolved in Islamabad's largest political rally in years. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of Pakistani cleric Tahir-ul Qadri rest on the third day of the protest rally in Islamabad on January 16, 2013. A populist cleric Wednesday urged Pakistani politicians to join tens of thousands taking part in the largest protest in Islamabad for years, ratcheting up the pressure on the government to step down. (ASIF HASSAN/AFP/Getty Images)

  • Pakistani students, civil society and Pakistan Muslim League Nawaz party activists light candles in the favor of democracy in Lahore on January 16, 2013. Pakistan's main opposition leader Nawaz Sharif demanded January 16, that the government immediately announce a timetable for elections. (Arif Ali/AFP/Getty Images)

  • A supporter of Pakistani cleric Tahir-ul Qadri dances to drums on the third day of the protest rally in Islamabad on January 16, 2013. A populist cleric Wednesday urged Pakistani politicians to join tens of thousands taking part in the largest protest in Islamabad for years, ratcheting up the pressure on the government to step down. (ASIF HASSAN/AFP/Getty Images)

  • Activists of the ruling Pakistan Peoples Party (PPP) burn tyres on a street at a protest rally in Lahore on January 16, 2013, against the Supreme Court order to arrest of the prime minister Raja Pervez Ashraf. Pakistan's top judge January 15, ordered the arrest of the prime minister over graft allegations, threatening to worsen turmoil as thousands of protesters demanded the government step down. (Arif Ali/AFP/Getty Images)

  • A Pakistani villager from the northwest mourns the death of a relative during a protest in the provincial capital Peshawar on January 16, 2013. Demonstrators said gunmen wearing military uniforms stormed homes in Bara Tehsil in Khyber Agency, some 30 kilometers from Peshawar and shot 18 villagers dead in an overnight raid. (A Majeed/AFP/Getty Images)

  • Supporters of moderate preacher Tahir-ul Qadri rest on the third day of a protest rally in Islamabad on January 16, 2013. Pakistani protesters rallied for a third day January 16 in the largest political demonstration seen for years in the capital, calling on the government to quit after the Supreme Court ordered the arrest of the prime minister. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of moderate preacher Tahir-ul Qadri prepare breakfast at dawn on the third day of a protest rally in Islamabad on January 16, 2013. Pakistani protesters rallied for a third day January 16 in the largest political demonstration seen for years in the capital, calling on the government to quit after the Supreme Court ordered the arrest of the prime minister. (ASIF HASSAN/AFP/Getty Images)

  • Pakistani Frionter Constables (FC) and policemen stand guard over a barricade of shipping containers on Constitution avenue on the third day of a protest rally in Islamabad on January 16, 2013. Pakistani protesters rallied for a third day January 16 in the largest political demonstration seen for years in the capital, calling on the government to quit after the Supreme Court ordered the arrest of the prime minister. (ASIF HASSAN/AFP/Getty Images)

  • A supporter of moderate preacher Tahir-ul Qadri waves this Pakistani national flag on the third day of a protest rally in Islamabad on January 16, 2013. An estimated 25,000 to 50,000 people have poured into Islamabad from across the country, devoted followers of moderate preacher Tahir-ul Qadri who is calling for the government to step down and radical reforms. It is the largest protest in the capital since the Pakistan People's Party won elections in 2008, ending a decade of military rule and forming what in March will be the country's first civilian government to complete a term in office. (ASIF HASSAN/AFP/Getty Images)

  • Supporters of moderate preacher Tahir-ul Qadri gather on the third day of a protest rally in Islamabad on January 16, 2013. An estimated 25,000 to 50,000 people have poured into Islamabad from across the country, devoted followers of moderate preacher Tahir-ul Qadri who is calling for the government to step down and radical reforms. It is the largest protest in the capital since the Pakistan People's Party won elections in 2008, ending a decade of military rule and forming what in March will be the country's first civilian government to complete a term in office. (ASIF HASSAN/AFP/Getty Images)