HERAT, Afghanistan: Taliban fighters clashed with government forces on the outskirts of Herat Friday forcing scores of families to flee, residents said, as the insurgents tightened a noose around the western Afghan city.

The Taliban have seized several districts on the outskirts of the city -- as well as two border crossings in Herat province adjoining Iran and Turkmenistan -- as they continue a sweep across the country.

Violence has surged since early May, when US-led foreign forces began a final withdrawal which is now almost complete.

An AFP correspondent in Herat said the Taliban and government forces were fighting on the road leading to the city airport, while residents said clashes were also going on in the nearby districts of Injil and Guzara.

"People there are terrified," said local Abdul Rab Ansari, who fled to the city from Guzara.

Afghan forces and militiamen of veteran warlord and anti-Taliban commander Ismail Khan have been deployed around the city of about 600,000 inhabitants.

Khan, who previously fought the Soviet occupation forces in the 1980s and then the Taliban during their hardline regime in the 1990s, has vowed to fight the militants again to counter their staggering advances in recent months.

"The fighting is heavy but they have not captured the district of Guzara so far," said Mohammad Allahyar, who also sought shelter in the city.

The United Nations Assistance Mission in Afghanistan told AFP that gunshots had been fired close to a UN facility in Herat.

"No UN personnel were engaged nor affected by the reported incident," it said.