Fierce fighting is ongoing between Afghan security forces and Taliban militants for control of a district centre in Ghazni province, in the country's south-east, officials said on Sunday.

The fight for control of the district of Ajristan began Thursday when 600 to 700 Taliban fighters attacked the district centre, Nasir Ahmad Faqiri, a provincial council member, told dpa.

He said lines of communication to the district centre were cut, but four helicopters carrying Afghan Special Forces landed in the district centre early Sunday and are fighting Taliban militants.

Aziza Maisam, another provincial council member, confirmed that commando forces had landed in the district centre and added that the district police chief and governor escaped, heading towards Shahristan distirct in Daikundi province.

"The Afghan army are the only ones fighting the Taliban at the moment," she said.

The district police station has fallen to the Taliban and some nine security force members were fighting the Taliban from the district governor's building, Ghulam Sakhi Ammar, another provincial council member, said.

Local officials said they expect heavy casualties, but that there is no word on the number of casualties from either side yet.

Taliban militants also set fire to homes belonging to security force members in the district.

Ghazni has seen intense fighting between Taliban and Afghan security forces in the past week.

At least 21 policemen were killed across five districts in Ghazni as the Taliban mounted attacks on Afghan security forces during 24 hours starting Tuesday.