40 killed as violence rages in Afghanistan

The rebels were operating in larger groups and "fighting hard" against security forces penetrating new areas, coalition spokesman Colonel Tom Collins told reporters in the capital Kabul.

The past weeks have seen some of the biggest battles in Afghanistan since the Taliban were removed from power by a US-led coalition in late 2001 for sheltering the Al-Qaeda terror network.

The surge in violence coincided with the launch of the biggest yet coalition and Afghan operation in the south, Mountain Thrust.

The operation had resulted in the killing of more than 90 militants since it kicked off in mid-May in four southern provinces, Collins said.

"People should expect significant fighting in certain areas of the south over the coming months," he said.

"Clearly the enemy is resisting the coalition and the Afghan national army's efforts in the areas that they haven't previously operated in," he said.

"We're seeing the enemy operate in larger groups. They're fighting hard, they're clearly trying to stop our efforts to move into certain areas."

Mountain Thrust involves thousands of coalition troops, mainly Americans, British and Canadians, and Afghan forces and is being conducted in southern Kandahar province -- the birthplace of the Taliban -- and Helmand, Uruzgan and Zabul.

An Afghan army commander said that Afghan and coalition forces had killed 20 Taliban Tuesday evening when they raided a Taliban hideout in southern Helmand province's Musa Qala district, which sees a lot of action.

"Their bodies with their weapons were left at the site," General Rahmatullah Raufi, commander of the army's southern corps, told AFP. An Afghan army soldier was also wounded.

About 3,300 British are deploying to Helmand to help Afghan forces build security and work on reconstruction.

A senior British commander also told embedded reporters in the province Tuesday that the arriving British deployment had met greater numbers of Taliban rebels than expected.

British troops were however still more than a match for the militants as seen in clashes earlier this month, the commander told reporters on condition of anonymity at a British base in Lashkar Gah, the capital of Helmand province.

The Taliban have claimed to have 12,000 fighters in southern Afghanistan alone but an army officer has said the number was more like 5,000 fighters in the whole country.

In other incidents a bomb fixed to a tanker supplying fuel to US forces exploded in eastern Nangarhar province on Tuesday as it crossed over from Pakistan, killing six people and gutting 10 trucks, a border police commander told AFP.