Fighting in Afghanistan this week has been among the most intense since the U.S. invasion over four years ago, with up to 300 people reported killed since last Wednesday.

The United States says it struck a blow against the Taliban on Monday when its warplanes killed as many as 80 people.

Afghans at the scene, however, say some of the victims were innocent civilians.

On Tuesday, news services reported new violence. The Associated Press reported that three health workers and a driver were killed when their vehicle struck a land mine near the capital of Kabul.

The Reuters news service quoted government officials who reported that Taliban guerrillas attacked a convoy of provincial officials and police in the southern province of Helmand, killing three policemen and wounding six.

On Monday as many as 80 Taliban fighters and civilians were killed in a strike by U.S.-led coalition aircraft on a rebel stronghold in southern Afghanistan, according to reports.

The governor of Kandahar told reporters that 50 Taliban fighters and 15 civilians were killed. At least 16 civilians were wounded in the airstrike, the governor added.

A statement from the Coalition Press Information Center said coalition forces conducted the operation near the village of Azizi, the third in a week, which "resulted in the unconfirmed deaths of possibly up to 80 Taliban members."

"Initial assessments have confirmed 20 Taliban killed with an unconfirmed 60 additional Taliban casualties."

Lt. Col. Paul Fitzpatrick, Combined Joint Task Force - 76 spokesman, said coalition forces were aware of media reports of civilian casualties "and are continuing to review assessments from ground elements in the region."

He said those people killed Monday "were active members of the Taliban network who conducted attacks against coalition and Afghan forces as well as civilians."

The network members had attacked Afghan government officials and collected explosives to be used in improvised explosive devices, he said.

According to the figures from coalition and Afghan officials, the new deaths before those on Tuesday brought the toll of militants, Afghan forces and coalition soldiers and civilians killed to more than 280 since Wednesday.