KABUL (AFP) - A powerful explosion which went off outside the Supreme Court and near the US embassy rocked the Afghan capital Kabul on Tuesday, witnesses said.

There were no immediate information on any casualties from the blast on the main road to the international airport. Witnesses told AFP they saw the wreckage of a car and buses with windows smashed.

On Monday seven Taleban insurgents were killed after launching a gun and grenade attack on military buildings near the airport's perimeter fence.

The response from Afghan security forces was widely praised as a sign of their growing professionalism as they take over responsibility from 100,000 US-led foreign combat troops who will pull out by the end of next year.

Kabul also came under attack on May 24, when Taleban militants launched a coordinated suicide and gun assault on a compound of the International Organisation for Migration.

A policeman, two civilians and all four militants died in that attack, and Afghan security forces won credit for an effective response.