An Afghan doctor and driver have died after fighters attacked their vehicle with rockets near the western city of Herat.

A third person was seriously wounded in the incident, which was condemned by Hamid Karzai, the Afghan president, as a "despicable act of terrorism".

The two dead worked for Malteser International, a worldwide relief agency based in Germany. The injured victim worked for the United Nations Children's Fund (UNICEF). All were travelling in a UN vehicle.

The vehicle was returning from a routine mission in the Badghis province when it was attacked.

Tom Koenigs, head of the UN mission in Afghanistan, said that he would do all he could to bring those responsible to justice.

About 45 aid workers - both Afghans and foreigners - have died in the country since 2002, Hashim Mayar, deputy director for the Agency Co-ordinating Body for Afghan Relief, said on Saturday.

PHOTO CAPTION

Afghan President Hamid Karzai speaks to the media in Kabul April 30, 2006. (Reuters)