Operation "Baaz Tsuka" (Falcon's Summit) was launched last Friday by hundreds of International Security Assistance Force (ISAF) and Afghan troops in the Panjwayi and Zhare districts of Kandahar province.

"We have cleared one large and two small villages of Taliban. We have killed about 50 Taliban," Nato spokesman Brigadier Richard Nugee told a press conference in Kabul.

The spokesman said there had been no Afghan army or Nato casualties during the operation.

The 31,000-strong ISAF is fighting a fierce Taliban insurgency alongside Afghanistan's fledgling army and 8,000 troops from the US-led coalition that ousted the Islamist regime in late 2001.

Nugee said ISAF forces, which took over from the coalition in Afghanistan's restive south and east earlier this year, would stay in Afghanistan as long as they were needed.

"We are here to stay for as long as the government of Afghanistan wants us to help them and that might, we anticipate, be beyond 2010," he said.

His comments come amid mounting concerns in western nations over increased Nato casualties in Afghanistan this year.

A stepped-up Taliban insurgency has claimed more than 4,000 lives during 2006, four times the previous year's toll. Around 1,000 of those were civilians while militant deaths make up the bulk of the rest.