The Afghan capital of Kabul is at risk of falling under an ongoing onslaught by hundreds of Taliban fighters, according to authorities.

Insurgents have burned down several dozen homes and beheaded at least 12 people in the province of Ghazni, southwest of Kabul.

Up to 700 Taliban fighters have attacked several villages over the past five days, in a bid to regain control over important opium growing areas, such as the southern province of Helmand and Kunduz in the north. At least 100 people are said to have died so far in the attacks.

"If there is no urgent help from the central government, the district [where the Taliban are fighting in Ghazni] will collapse," deputy police chief of the area Asaddullah Safi told Reuters news agency.

Ahmadullah Ahmadi, provincial deputy governor, said the provincial government had requested help to push back the insurgents.

"We have asked repeatedly for helicopters to evacuate the wounded, but so far nothing has been done," Ahmadi said.

There are fears that the Taliban could launch an attack on the capital if it takes Ghazni.

The growing threat is posing a challenge for the country's new unity government between President-elect Ashraf Ghani and former rival Abdullah Abdullah just ahead of the complete withdrawal of NATO coalition troops.

"Peace with the Taliban requires a strong government. At the moment the Taliban think they can fight in every province and they believe they can overthrow the government," said Haji Mohammad Mohaqiq, Abdullah's running mate and the leader of Afghanistan's ethnic Hazara minority.

sb/crh (Reuters, AP)