Warning: Graphic Images
A British citizen is among those killed in a suicide bombing in Afghanistan after an Embassy vehicle was attacked in the country's capital of Kabul this morning.
The Foreign Office said a number of staff were hurt when an explosion hit, with at least five people - including one British citizen - killed in the attack, the Afghan Interior Ministry was reported to have said.
Some reports claimed the attack was staged by a bomber riding a motorcycle, while others suggested a car packed with explosives was rammed into the embassy vehicle.
A Foreign Office spokeswoman said: "We can confirm that a British Embassy vehicle has been attacked in Kabul. A number of staff have been injured.
"We are working with the Afghan authorities to establish details of the incident."
The explosion caused parts of the city to shake and sent a plume of dust and smoke into the air.
Photographs shared on social media apparently from the scene showed burning wreckage including a car, debris strewn across the ground and bloodied casualties.
An Afghan national working for the embassy in Kabul was also killed, Philip Hammond said, condemning the strike as "appalling".
Hammond said: "This morning a British Embassy vehicle was attacked in the Afghan capital, Kabul.
"I am deeply saddened to confirm that a British national civilian security team member and an Afghan national working for the embassy were killed in the incident. A second British member of the security team was injured.
"I condemn this appalling attack on innocent civilians supporting our diplomatic activity. The families of the victims have been informed and my thoughts are with them. The Foreign Office will do everything it can to support them.
"This outrage brings home to us once again the courage and perseverance of the people of Afghanistan and members of the international community who support them, who have lived together through decades of conflict.
"We will not allow such inhumanity to deter us from continuing our partnership with the government of Afghanistan.
"I have nothing but admiration for the staff of the embassy, British and Afghan, who work at great personal risk to help build a better future for Afghanistan."
A second British member of the security team was injured when the vehicle was targeted by a suicide bomber.
The Taliban were reported to have claimed responsibility for the brutal attack.
Deputy interior minister General Mohammad Ayub Salangi said: "Foreign vehicles were targeted by a suicide attacker on a motorcycle."
Others took to Twitter to say their condolences and condemn the attack:
Franz-Michael Skjold Mellbin, the European Union's special representative in Kabul, wrote on Twitter:
Sir Simon Fraser, head of the UK Diplomatic Service, tweeted:
Mustafa Deveci, a journalist in the area, told Sky News the attack took place on a "very busy" road.
He said: "I saw five or six civilian cars were damaged."
It is the latest in a wave of attacks to hit Kabul as the majority of foreign combat troops withdraw from Afghanistan by the end of the year.
In recent weeks, insurgents have launched attacks on military convoys and compounds housing foreign service companies and their international employees.
British embassies and staff have been targeted in trouble-spots around the world in recent years, with Kabul among them.
In August 2008 a car bomb attack near the embassy in the Afghan capital left four people dead, although none were British personnel.
In November 2011 the embassy in the Iranian capital Tehran was closed after it was stormed by a mob of protesters.
In April 2010 the then British ambassador to Yemen, Tim Torlet, escaped unharmed when a suicide bomber wearing a school uniform detonated an explosives belt as he made his way to work in the capital Sana'a. The following October, his deputy, Fionna Gibb, escaped a rocket attack in the city.
Last year the embassy in the Arab country was closed by the Foreign Office during the Islamic festival Eid, amid ''continuing security concerns''.
On November 2003 the British Consul-General in Turkey, Roger Short, was killed by a suicide car bomb in Istanbul blamed on al Qaida which left 60 others dead and hundreds injured.