Taliban fighters killed at least 18 Afghan security personnel Wednesday in two attacks on checkpoints in the north, officials said, the latest violence ahead of expected peace talks.

In one pre-dawn raid, militants killed 12 Afghan security force members when they stormed a checkpoint in Jawezjan province, Maroof Azar, spokesman to the governor, told AFP. He said four security personnel were captured by the militants and five Taliban fighters were killed in the fighting.

The ministry of defence confirmed the attack and said six of its soldiers were among the dead. The Taliban spokesman for the group's fighting forces, Zabihullah Mujahid, gave a higher toll. Separately, Taliban fighters were blamed for a raid on an army outpost in Kunduz.

Six soldiers were killed in fighting that lasted about five hours, said Aminullah Iddin, a member of the provincial council. Army spokesman Hadi Jamal confirmed the attack, saying four Taliban fighters were also killed.

The Taliban has not commented on that raid. The latest bloodshed comes as the insurgents and the government inch closer towards potential peace negotiations. The much-delayed talks aimed at ending the conflict are expected to begin once the two sides complete an ongoing prisoner swap accelerated after a brief ceasefire last month.

Officials claim the Taliban have stepped up attacks in recent days, although there has been an overall drop in violence across the country since the ceasefire ended.