KABUL -- A Dutch soldier of the international force guarding Kabul and an Afghan interpreter were wounded on Friday in an explosion in the south of the capital.

Lieutenant Colonel Thomas Lobbering, a spokesman for the International Security Assistance Force (ISAF), said the men were on a patrol when the blast occurred.

"We don't know at this stage what caused the incident. Two persons, one Dutch soldier and an Afghan interpreter have been wounded," he told Reuters.

He said he did not have any details of the condition of the wounded men.

Witnesses said ISAF troops blocked the street where the blast took place, which is lined by shops and mud houses.

Lobbering said he could not say if the incident was a hostile act.

The blast took place a day after the first anniversary of the death of five ISAF soldiers who were trying to destroy unexploded ordnance.

Germany and the Netherlands jointly lead the 4,700-strong ISAF.

The German commander of the force, Lieutenant General Norbert Van Heyst, warned this week that extremists might launch attacks on ISAF if the United States attacked Iraq.

The United States is leading a coalition force in Afghanistan hunting remnants of Osama bin Laden's Al-Qaeda network, the former Taleban regime and guerrillas loyal to a renegade warlord.