KANDAHAR, Afghanistan -- Fighting raged across southern Afghanistan on Saturday with attacks on government offices and a police convoy killing a district chief and 15 others -- raising the death toll from two days of battles to 37, officials said.
Government officials said more than 200 rebels were fighting 250 police and Afghan soldiers, as well as U.S. forces.
The violence comes after an unprecedented spate of suicide bombings and underscores the massive challenge facing international forces in bringing peace to the troubled country four years after the Taliban was ousted.
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 the 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 neighboring 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.
Also in Kandahar, a Taliban commander, Abdul Samad, was killed by border forces as he tried to enter illegally from neighboring Pakistan with about 10 other militants, Kandahar Gov. Asadullah Khalid said. The other insurgents fled back across the frontier.
The toll from the initial fighting in Helmand on Friday rose to five police and 16 insurgents dead, and 16 police wounded, Akhund said.
The U.S. military confirmed it was involved in the fighting on Friday, but asked about its involvement in the violence on Saturday, spokesman Lt. Mike Cody said he had no details.
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 to be deployed there later this year to take over from U.S. forces.
Fighting last year left some 1,600 people dead, the highest death toll since 2001, as militants stepped up their campaign against the U.S.-backed central government.
Afghan authorities blame much of the violence on foreign militants who have come here to bolster the insurgency. Officials said this week after interrogating an Iraqi caught trying to sneak into the country that a large group of Arab al-Qaida militants are believed to be on their way here.
The latest fighting comes just days after an international donors' conference in London ended with $10.5 billion in new aid pledged -- much of it for improving security.