Taliban fighters killed a German peacekeeper and three Afghans in two car bombings and British troops opened fire to repel a possible attack at their camp in the Afghan capital on Monday, officials and witnesses said.

The suicide bombings came about an hour apart on the same stretch of road east of Kabul. On each occasion, the attackers rammed a car into a vehicle belonging to the NATO-led International Security Assistance Force.

"Both of the incidents were suicide acts," said Gen. Mahboub Amiri, chief of the capital's rapid-reaction police force.

The violence coincided with rejection by the Taliban, the Islamic militia ousted from power by a U.S.-led invasion in 2001, of President Hamid Karzai's call to halt its insurgency and join a national reconciliation process.

"We have plans for more of the same," Mullah Dadullah, a Taliban commander, said by satellite telephone from an undisclosed location.

The first blast on Monday killed the German soldier and wounded two others, according to Maj. Andrew Elmes, a spokesman for the NATO-led force. Three Afghan civilians were also wounded, local officials said.

Shortly afterward, three Afghans, including a young boy who Elmes said succumbed to injuries, were killed in another attack on Jalalabad Road, where several NATO contingents have bases.

Police said two peacekeepers were wounded, and witnesses said two Afghan journalists also were hurt.

In Athens, a Greek Defense Ministry source said two Greek soldiers were slightly injured when insurgents attacked their vehicle just outside Kabul. Greece has 130 soldiers in the NATO-led force.

British Defense Minister John Reid said a camp for British troops had also come under threat.

"I can also tell the House that British troops have opened fire in order to prevent unauthorized entry to . . . a camp in Kabul," Reid told Parliament.

The peacekeeping force, stationed in Kabul since the 2001 invasion, has been targeted by suicide bombers before. In 2003, four German soldiers were killed and more than 30 were wounded in the worst such incident.

The attack on Monday brought to 18 the number of Germans killed in attacks or accidents in Afghan peacekeeping operations.

British soldiers secure the area where a German military vehicle was hit in a suicide bombing near Kabul, killing one soldier. Another suicide bombing on the same road about an hour later killed three Afghans, including a young boy.