KABUL, Afghanistan — A bomb exploded near a NATO peacekeeping convoy in northern Afghanistan on Wednesday, killing one Afghan civilian and wounding 12 people, including a German peacekeeper, officials said.

A powerful bomb planted on a bicycle went off around 1:30 p.m. in the northern city of Kunduz near three NATO forces' vehicles parked near a bazaar, said Mutalib Beg, the provincial police chief. He said one Afghan man was killed and 11 other Afghans wounded.

Lt. Riccardo Costa, a media officer in Kabul for the NATO-led International Security Assistance Force, said one foreign soldier was also slightly injured and was getting medical treatment. He declined to give the soldier's nationality.

A spokesman for the German military in Potsdam, Germany, said one German soldier was wounded in an attack on a military vehicle and at least one Afghan was killed.

Costa said six peacekeepers and two Afghan colleagues had been travelling in the vehicles that were attacked.

The NATO-led multinational force currently provides security in the relatively stable north and west of the country, but is coming under increasing attack.

It is boosting its troop numbers from 9,000 to 16,000 troops this year, and is gradually moving into the volatile south of the country, currently patrolled by U.S. and Canadian forces, where Taliban rebels are active.