US hammers al-Qaeda bastion

The mountains have been pounded day and night

US-led forces have carried out the heaviest air strikes yet against Taleban and al-Qaeda fighters holed up in the mountains and caves of eastern Afghanistan.

A BBC correspondent near the battle zone said overnight bombing was the most intense so far as the operation entered its sixth day.

Thousands of Afghan soldiers are reported to be joining US troops

Flashes lit up the night sky and dozens of helicopters flying into the combat zone were believed to have been carrying more US and allied troops.

Our correspondent in Gardez, Adam Brookes, says the Taleban and al-Qaeda forces have broken up into small, well armed units, which are carrying out highly mobile guerrilla warfare using networks of caves.

And he says that American and coalition troops were now engaged in close quarter combat with them.

An Afghan commander who brought in men from his base north east of Gardez, estimated that about 5,000 Afghan troops were preparing to join the US-led force.

Upper hand

As the battle raged, the Pentagon said opposition fighters were putting up stiff resistance in the snow-capped mountains.

US estimates of enemy strength began at 150 to 200 but were later increased to between 600 to 700.

The fighters are believed to have regrouped in the mountains after the Taleban fell back from their spiritual centre of Kandahar in December.

Reports say the fighters are armed with AK-47 automatic rifles, mortars, rocket-propelled grenades and shoulder-fired anti-aircraft missiles.

Afghan forces fighting with the Americans have been offering residents in Paktia province $4,000 rewards to turn in al-Qaeda members.

Major General Frank Hagenbeck, commander of the operation, which has been named Operation Anaconda, said US-led troops had gained the upper hand after killing about half the enemy forces.

"We own the dominant terrain in the area," he said. "We truly have the momentum at this point."

General Tommy Franks, the most senior US field commander in the Afghan campaign, said on Wednesday that the number of American troops committed to the operation had been increased to about 1,100.

Allies determined

"I think the days ahead are going to continue to be dangerous for our forces but the alternative to taking such a risk is not acceptable," General Franks said.

In Kabul, Afghan interim leader Hamid Karzai said the coalition was prepared to take as long as necessary to crush al-Qaeda.

"It may be a day or two, or it may take longer," he said. "We are determined."

The US lost seven men when two helicopters were downed

Neither the former Taleban leader Mullah Mohammed Omar nor al-Qaeda leader Osama bin Laden are believed to be in the area.

Eight US servicemen have been killed in the operation so far - seven in two attacks on helicopters on Monday and another in a ground battle on Saturday.

Nine US soldiers have been injured.

The number of Afghan casualties is not known.

General Hagenbeck said that the offensive had been launched following intelligence that Taleban and al-Qaeda fighters had been plotting terrorist attacks against the new interim administration in Kabul.