International and Afghan troops forged ahead with an offensive against the Taliban near the Pakistan border on Tuesday, with a governor insisting 150 rebels had been killed in the past week.

US Marines and British troops under NATO command launched a significant new operation two weeks ago in Garmser district in southern Helmand province, a key battleground for a Taliban-led insurgency and an opium-producing centre.

Soldiers in a separate US-led coalition have also reported several engagements in the area in the past week. They said Tuesday they had killed a dozen rebels in Garmser on Monday.

The international forces helping Afghanistan fight an insurgency led by the Al-Qaeda-backed Taliban normally do not issue death tolls from their engagements, saying they want to avoid a "body count."

But Helmand governor Gulab Mangal told AFP on Tuesday that 150 Islamic rebels, most of whom he said were Al-Qaeda-linked Arab and Pakistani fighters, had been killed in military action in Garmser in the past week.

"In the past seven, eight days, we have killed about 150 insurgents, most of them foreign fighters," he said, citing "intelligence."

"We have intelligence reports that more than 500 enemy fighters, most of them foreign terrorists, are in the district," he said. "The operation will continue until the district is cleared of these destructive elements."

The Afghan army, operating with some of the international deployments, could not be reached for comment. NATO's International Security Assistance Force could not verify the numbers.

"The Marines continue to gain ground down in Helmand," ISAF Major Martin O'Donnell told AFP, adding that he could not comment on death tolls.

The Marines said: "While we are continuing operations to clear the Taliban from the Garmser district, it is not ISAF nor US Military policy to comment on enemy casualties as we do not consider this a reliable measure of success."

Information is difficult to independently confirm in Garmser, a remote desert province where there are few roads and government authority is limited.

The military says Garmser is a rebel gateway into Afghanistan, bring fresh recruits and weapons from Pakistan where extremist rebels are said to have bases.

Some of Afghanistan's opium, which makes up to 90 percent of world supply, is meanwhile routed out of the country across the southern border.

A local resident contacted by AFP by telephone said "more than 100 Taliban have been killed in the past several days."

"They were killed in several different attacks and air bombardments," said the man, who identified himself as Abdul Baqi.

He was speaking from Lashkar Gah, the provincial capital located about 50 kilometres (35 miles) north of Garmser, where he was taking refuge from the fighting.

The government said Monday about 6,000 people have fled their homes in Garmser, fearing the military operations.

The Taliban insurgency, launched after the rebels regrouped following their ouster from government in a US-led invasion in late 2001, is strongest in the areas bordering Pakistan.

But it has made inroads into several other provinces.

In Wardak, adjoining Kabul, two Taliban and two policemen were killed in a clash that erupted Monday after the rebels attacked a foreign military convoy, the provincial police chief Muzaffarhuddin Yamin said.