The assassination of one of Afghanistan's vice presidents will not destabilise its fledgling government, the foreign secretary has insisted.

Jack Straw described the shooting of Abdul Qadir by two men on the streets of Kabul as a "terrible and shocking event".

Straw predicted that president Hamid Karzai's government would not be deterred as a result.

"These are terribly tragic and shocking events but it is in nobody's interests that we should bow to the agenda of the terrorists and the criminals," he said.

"I am in no doubt about the determination and competence of President Karzai and his government to stay on the path of progress and reconstruction."

He said Britain had already sent messages of support to the Afghan government and rejected claims the assassination had been able to happen because British troops pulled out too soon.

"We only handed over after very careful consideration by ourselves and the UN Security Council when everybody was confident that the Turkish forces, who are very proficient, expert and large, were able to take this job on," he said.