Kabul tense after weekend bombing

Government offices, Nato bases and restaurants are all possible targets

Security has been tightened across the Afghan capital, Kabul, following Sunday's bomb explosion outside the offices of an American security firm.

Nato-led peacekeepers say at least three Americans and three Afghans died in the blast, claimed by the Taleban.

But there is confusion about the final casualty toll, with reports of several more dead including some Nepalis.

Kabul is tense with extra checkpoints and troops patrolling the streets, and increased security outside embassies.

President's shock

The US embassy and other international organisations in Kabul have told staff to avoid all but essential movement in the city following the blast.

In pictures: Kabul blast

The BBC's Andrew North in Kabul says that some embassies now have international peacekeeping troops outside in addition to their usual guards.

Security was especially tight around another building in the city, linked to Dyncorp, the US firm hit by Sunday's explosion.

Afghan President Hamid Karzai says he is deeply disturbed by the attack.

Dyncorp provides his bodyguards and trains the new Afghan police force.

Arrest

The immediate blast site in Kabul's Shar-e-Naw district is now cordoned off as Afghan and foreign investigators work out how the bombers got so close to what was a heavily-guarded building.

This cowardly attack will not deter US participation in the ongoing effort to help Afghanistan stand on its own feet US Afghanistan Ambassador Zalmay Khalilzad

Agents from the American FBI, Afghan police and explosives experts from the peacekeeping force are all taking part.

A Canadian peacekeeping spokesman said the bomb had been set off remotely but it is still not known if it was contained in a car or a truck.

One man was detained at Kabul airport late on Sunday, he said, with traces of explosives on his hands.

But it is not clear whether he had any ties to the attack.

Afghanistan's hardline former Taleban rulers said one of their fighters had detonated the remote-controlled bomb, but they denied it was a suicide mission.

Senior Taleban spokesman Hamid Agha told the BBC the man had driven an explosives-laden vehicle up to a guesthouse used by US servicemen and escaped after parking it there.

US pledge

US Ambassador Zalmay Khalilzad said he was shocked by the attack.

The Kabul blast was heard across the city

"This cowardly attack will not deter US participation in the ongoing efforts to help Afghanistan stand on its own feet," he told the Associated Press.

The Kabul attack came just hours after an explosion at a school in southern Afghanistan killed at least 10 people, nine of them children, the US military said.

A spokesman said Saturday's blast in south-eastern Paktia province was now believed to have been caused by an improvised bomb.

Taleban did not carry out the attack and did not target children at religious schools, its spokesman Hamid Agha said.

The Taleban were ousted from power by a US-led campaign in 2001 and have since waged a guerrilla campaign against foreign and Afghan government targets.