Kandahar, Afghanistan ? Violence raged across southern Afghanistan, killing 29 suspected militants, two British soldiers and two Afghan troops, and the U.S.-led coalition pressed on with its largest military offensive here since 2001, officials said Tuesday.

Resurgent Taliban militants and extremist allies are waging their fiercest campaign against Afghan and coalition forces since the extremist regime was toppled after the Sept. 11, 2001, attacks for hosting Osama bin Laden and his al-Qaida terrorists.

British forces came under attack early Tuesday in the Sangin valley of the southern Helmand province, where Britain has 3,300 troops, the British Defense Ministry said.

Two British soldiers were killed and one wounded in the firefight, said Capt. Drew Gibson, a military spokesman. Five suspected militants also were killed.

The last British combat death was June 11. In all, 10 British soldiers have been killed in Afghanistan since November 2001.

Militants also ambushed an Afghan army patrol in Musa Qala, a remote Helmand provincial district about 20 miles north of Sangin.