Government officials said more than 200 rebels were fighting 250 police and Afghan soldiers, as well as US forces, making it the biggest battle this year in Afghanistan.

American war planes bombed suspected Taliban militants before dawn Saturday, killing eight of them, said Khan Mohammed, a police chief in Helmand province.

At the same time, militants attacked a government office in Helmand province's Musaqala district, killing the government chief and wounding four police, said Amir Mohammed Akhund, deputy governor of southern Helmand province.

Hours later, insurgents attacked the main government office in neighbouring Nauzad district, setting off a two-hour gunbattle that left one policeman and three suspected Taliban dead, he said.

Militants used a remote-controlled bomb to attack a police convoy in Kandahar, the main city in southern Afghanistan and a former Taliban stronghold, said Sher Mohammed, a police officer.

A district police chief in the convoy was unhurt, but a woman and a child who were walking in the area were killed, and three other passers-by were wounded, he said.

The toll from the initial fighting in Helmand on Friday rose to five police and 16 insurgents dead, and 16 police wounded, Akhund said.

Kandahar and Helmand are hotbeds of the anti-government insurgency and the drug trade, underlining the challenges that will face Nato peacekeepers from Britain and Canada who are set to deploy there later this year to take over from US forces.

Four years after the ouster of the hardline Taliban regime, its militant supporters are still fighting the US-backed central government, particularly in the volatile south and east of the country. Last year, more than 1,600 people died in the violence, the highest death toll since 2001.

Meanwhile, at least 33 people have died in the past week in severe weather in Afghanistan's northern Badakshan province, including 15 villagers who were killed in an avalanche, a provincial official said Friday.

The bodies of three people who had died from cold were recovered late Thursday, said the provincial head of administration, named only Attaye.

Another 15 people died from cold earlier in the week and the bodies of 15 more were recovered after an avalanche destroyed several homes in about five villages late Monday, he said.

"Up to now we have received 33 bodies," he said, warning the figure could increase as information came in from parts of the province that were inaccessible, even by horse, because of the heavy snow.

The administration planned to use helicopters to begin ferrying food and other aid into cut-off villages on Saturday, he said.