An explosion has rocked the diplomatic area of the Afghan capital, Kabul, police have said, with at least 10 people killed and 60 injured, the BBC News reported.

Police said it was a suicide attack on a foreign military convoy which was traveling through the area.

A health ministry official said nine Afghans and one foreigner were killed.

A senior NATO official said that three of its contractors had been killed in the attack in the Macrorayan district, but gave no further details.

No group has said it carried out the attack, although in recent months Kabul has been regularly targeted by the Taliban in a series of bombings.

Before that, there were three deadly attacks in the city - on a police academy, a NATO base and an Afghan army base that killed at least 50 people.

The Taliban has stepped up its campaign of violence in recent months, taking advantage of the warmer weather of spring and summer. It has made some military gains, especially in northern Afghanistan.