Updated

Fierce fighting involving U.S. warplanes and Afghan troops in southern Afghanistan left at least 16 suspected Taliban rebels and three police dead, an official said Friday.

Amir Mohammed Akhund, deputy governor of southern Helmand province, said more than 250 Afghan police and army troops were hunting dozens of militants in Sangin district, and U.S. planes had bombed the area.

Afghan forces had recovered the bodies of 16 dead militants, including local Taliban commander Mullah Thorjan, he said.

Thirteen Afghan forces and four Taliban were wounded, he said.

The clashes in Helmand, a hotbed of the anti-government insurgency and the drug trade, underline the challenges that will face NATO peacekeepers from Britain set to deploy there later this year.

Fighting began Thursday when police were deployed to the Haji Fateh area to search for Taliban rebels hiding there, said Ghulam Muhiddin, the chief of administration in southern Helmand province.

Local police chief Abraham Jan said insurgents ambushed a police convoy.

Clashes intensified Friday as Afghan army forces joined a search operation against the militants, with U.S. support.

A U.S. military spokesman, Lt. Col. Jerry O'Hara, said American forces, including A-10 war planes, responded to an initial attack on Afghan security forces by up to 30 militants.

He said there were no reports of casualties among the U.S. troops, and the fighting was ongoing.

Four years after the hard-line Taliban regime was ousted, its militant supporters are still fighting for control of the U.S.-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.

NATO peacekeepers, which currently help maintain security in Afghanistan's relatively stable north and west, are fanning out into southern provinces, which have recently faced a wave of suicide attacks.

Britain announced last week it would deploy about 4,000 additional troops to Afghanistan after it takes control of NATO's mission there in May. It will operate a regional base in Kandahar and a so-called provincial reconstruction team in neighboring Helmand, which also is an important center of illicit opium production.

The deployment could pave the way for a reduction in the U.S.-led coalition force in Afghanistan charged with hunting Taliban and al-Qaida fighters. The coalition currently numbers about 20,000 troops.