NATO says a suicide bomber has targeted U.S. special forces north of the Afghan capital but there were no casualties among the troops, according to The Associated Press.

Maj. Bryan Woods, a spokesman for the international alliance, says the bomber and insurgents armed with small caliber weapons attacked a Special Operation Forces convoy as it was returning to base in the northern Kapisa province on Monday, May 13.

Qais Qadri, spokesman for the Kapisa governor, said one civilian was killed in the incident.

Woods said he could not confirm the death but said the special forces returned safely to their base "after engaging the enemy."

Attacks by Taliban insurgents have increased in recent months as the fighting season moves into high gear.