Clashes in Lebanon's capital Beirut and the northern city of Tripoli have left seven people dead and dozens more injured as the army warned of "unprecedented" tensions in the country.

The military are lining the streets of the capital in a bid to force gunmen off the streets and quell the violence as fears grow that Syria's civil war could spill over the border.

Unrest began on Friday after a senior intelligence chief was murdered in a car bomb, an attack many see as being orchestrated by Syrian elements.

violence lebanan

A 10-year-old boy holds a machine gun in Tripoli as Lebanese troops tried to contain the violence

Security official Wissam al-Hassan had recently helped to bring about the arrest of one of Syria's top allies in Lebanon on suspicion of planning to carry out terrorist attacks.

Violence erupted following the funeral of al-Hassan on Sunday after security forces clashed with protesters angry at Syria's perceived role in the killing.

Lebanese soldiers fired bullets in the air and launched tear gas at mourners as protesters tried to storm a government office demanding the resignation of Prime Minister Najib Mikati.

beirut

Protestors believe Syrian elements are responsible for a car bomb last week

In a statement on Monday, the army said: "The country is going through a decisive and critical time and the level of tension in some regions is rising to unprecedented levels".

It warned "all political leaders to be cautious when expressing their stances and opinions.. because the fate of the nation is at stake" reported the BBC.

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  • Lebanese security forces fire in the air during clashes after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • An injured Lebanese woman is carried away by protesters during clashes with security forces after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Lebanese security forces take aim during clashes after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Lebanese protesters pull a barbed-wire barrier during clashes after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • A Lebanese protester hurls a stick during clashes with security forces after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Lebanese protesters throw sticks and rocks during clashes with security forces after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Lebanese security forces fire in the air during clashes after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Police and protesters clash after the funeral of Brig. Gen. Wissam al-Hassan in Beirut, Lebanon, Sunday, Oct. 21, 2012. (AP Photo/Maya Alleruzzo)

  • A Lebanese protester throws a tear gas canister back at security forces during clashes after the funeral of Brig. Gen. Wissam al-Hassan who was assassinated on Friday by a car bomb in Beirut, Lebanon, Sunday Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Police and protesters clash after the funeral of Brig. Gen. Wissam al-Hassan in Beirut, Lebanon, Sunday, Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Police and protesters clash after the funeral of Brig. Gen. Wissam al-Hassan in Beirut, Lebanon, Sunday, Oct. 21, 2012. (AP Photo/Maya Alleruzzo)

  • A Lebanese honor guard carries coffins wrapped with Lebanese flags of Brig. Gen. Wissam al-Hassan and his bodyguard, Ahmad Sahyouni, who were assassinated on Friday by a car bomb, during their funeral procession at Martyrs' Square in Beirut, Lebanon, Sunday, Oct. 21, 2012. Thousands of Lebanese waving the national flag packed a central square in downtown Beirut Sunday for the funeral of a top intelligence official assassinated in a car bombing that many blame on the regime in neighboring Syria. (AP Photo/Bilal Hussein)

  • Police and protesters clash after the funeral of Brig. Gen. Wissam al-Hassan in Beirut, Lebanon, Sunday, Oct. 21, 2012. (AP Photo/Hussein Malla)

  • Members of Lebanese police intelligence division units, and other police officers gather around the two coffins that wrapped with Lebanese flags of Brig. Gen. Wissam al-Hassan and his bodyguard Ahmad Sahyouni who were assassinated on Friday by a car bomb, during their funeral processions at the Lebanese police headquarters in Beirut, Lebanon, Sunday, Oct. 21, 2012. Thousands of Lebanese waving the national flag packed a central square in downtown Beirut Sunday for the funeral of a top intelligence official assassinated in a car bombing that many blame on the regime in neighboring Syria. (AP Photo/Hussein Malla)