Four suicide attackers stormed an army recruitment centre in northern Afghanistan sparking a gun battle that left two soldiers dead and three others wounded, officials said.

"Four bombers attacked the recruitment centre. Three of them have been shot dead and one is still resisting," Hameedullah Danishi, the deputy provincial governor, told AFP early on Sunday.

Kunduz is one of the most volatile provinces in the relatively peaceful north of Afghanistan.

"So far two Afghan soldiers have been killed and three are wounded," Mahboubullah Saeedi, the spokesman for the provincial governor, said.

In a separate assault, a suicide attacker opened fire on an army bus in the capital Kabul. He was shot by policemen and his explosives detonated setting two vehicles ablaze, interior ministry spokesman Zemarai Bashari told AFP.

Bashary did not give any figures on casualties and said police had cordoned off the area and were still assessing the damage and impact of the blast.