Remnants of Afghanistan's ousted Taleban government have claimed responsibility for Sunday's suicide bombing that killed five Afghan security officials in Kabul, and they are vowing to carry out more attacks.

News reports quote Taleban spokesmen as saying militants are in the Afghan capital, ready to launch suicide attacks against foreign forces and local officials, as well as aid workers.

The five security officers who died Sunday were killed near Kabul Airport when a man they arrested detonated a bomb in their car.

The attack was the deadliest since June when a suicide bomber killed four German members of the International Security Assistance Force in Kabul, and wounded dozens of other people.

Officials blame the suicide bombings and other attacks on Taleban and al-Qaida terrorist network fighters.

Meanwhile, delegates to Afghanistan's loya jirga, or grand assembly, are preparing to vote on a proposed new constitution, that would pave the way for democratic elections next June.

Media reports say Afghan President Hamid Karzai appears to have persuaded most of the assembly's 502 delegates that the country's presidency should have broad powers in the future system of government.