Two bombs rigged to parked bicycles targeted NATO vehicles in Afghanistan's capital on Monday as a clash between police and militants in the south left 11 suspected Taliban and one policeman dead, officials said.
The clash in the mountains of southern Helmand province also left three wounded, said the deputy governor Amir Mohammed Akhunzanda.
Police arrested three suspected Taliban and recovered weapons, he said.
Over the past year, a growing insurgency has gripped the country's south and east, but Kabul, patrolled by thousands of NATO-led foreign troops, has been largely spared.
However, a series of recent bombings have rattled the capital, the latest on Monday. The first bike bomb blast struck Kabul's northern neighborhood of Khayrkhana as a NATO patrol passed by, smashing the windows of a nearby car, police official Ali Shah Paktiawaal said.
Three soldiers were slightly hurt, NATO said, adding a second bomb at the scene was discovered and disarmed, NATO said.
Another bomb-rigged bicycle blew up as a NATO vehicle was passing on a main road near a UN office, an Interior Ministry spokesman said.
The bomb exploded prematurely and did not cause any damage or casualties, he said, adding a suspect had been arrested. NATO confirmed the attempted attack.
In southeastern Paktika province, a suicide car bomber targeted Afghan troops shopping in a bazaar on Monday, wounding six soldiers and one civilian, an official said.
The bomber, driving a taxi, drove to within 40 meters of the soldiers in Barmal district before his vehicle exploded, said Sayed Jamal, the governor's spokesman.