More than 1,000 stone-throwing Afghans tried to break down an outer gate at the main U.S. base here Tuesday while demanding the release of eight detained villagers, and Afghan troops fired warning shots and used clubs to beat the mob back. U.S. troops also fired into the air.

It was not immediately clear if there were any casualties in the melee outside the base's main gate as protesters chanted "Die America!" Black smoke billowed from burning tires. An Associated Press reporter was hit by a stone and an AP photographer was punched by a protester.

In southern Afghanistan (search), meanwhile, a provincial governor said about 50 suspected insurgents and two Afghan soldiers died during an overnight battle. It was one of the deadliest clashes in recent fighting between the government and militants heading into parliamentary elections.

Attempts to confirm the casualty toll with other Afghan officials or the U.S. military were not successful. Death tolls reported by U.S. and Afghan officials can vary, with the U.S. numbers frequently lower.

The violence in Bagram (search) erupted when six U.S. military vehicles tried to enter the base. Demonstrators massed outside to protest the arrests threw stones at the convoy and soldiers in the vehicles fired into the air with handguns.

The convoy sped into the base and the mob chased after them, trying to push down a metal gate guarded by Afghan troops. Some soldiers beat the protesters with clubs and several fired assault rifles into the air as they shouted for the protesters to go home. Most dispersed.

The eight men arrested late Monday "had materials used to make improvised explosive devices in their possession and are thought to be planning future attacks against coalition forces," the U.S. military said in a statement.

Demonstrators said they were angry that American soldiers arrested the men without consulting local authorities.

"We have supported the Americans for years. We should be treated with dignity," said Shah Aghar, 35. "They are arresting our people without the permission of the government. They are breaking into our houses and offending the people. We are very angry."

The U.S. statement said the military tried to contact local Afghan authorities before the raid but was unable to do so.

There has been little violence in the Bagram area since U.S. forces helped oust the Taliban regime at the end of 2001 and took control of the base, where hundreds of Afghans are employed to clean, construct buildings and do other jobs.

One protester, Abdul Rahman, said that if the U.S. forces continued to raid people's houses, Afghans would launch a "holy war against them as we did against the Soviets and Taliban."

Thousands of American and other foreign soldiers live at the base, which is surrounded by several razor-wire fences and areas outside the perimeter remain mined from Afghanistan's civil war and Soviet occupation. The main entrance is a series of heavily guarded checkpoints.

In the southern city of Kandahar (search), Gov. Jan Mohammed Khan said the nighttime battle in Uruzgan province's Dihrawud district came during an offensive against a rebel camp. In addition to the deaths, about 25 suspected insurgents were captured, he said.

An American military spokeswoman said she had no details. A U.S. statement issued Monday said heavy fighting in that area had killed one American service member, an Afghan soldier and 11 rebels. Three Americans and one Afghan soldier were wounded, it said.

Elsewhere, police arrested 10 suspected Taliban insurgents after clashes in southeastern Zabul province, said Ali Khail, a spokesman for the provincial governor.

In neighboring Kandahar province, Taliban guerrillas attacked an Afghan patrol late Monday, triggering a battle that left an Afghan soldier dead and a police officer badly wounded, said deputy district chief Haji Lala Khan.

A candidate in the Sept. 18 election was killed in eastern Paktika province Tuesday when a roadside bomb blew up next to his vehicle as he drove his sick mother to hospital, police chief Malik Khan said. The mother was wounded.

More than 800 people have died in an upsurge in violence since March.