Intelligence officials say a US drone has fired missiles into Pakistan's South Waziristan region on the Afghan border, killing at least 13 people and injuring dozens others.

The drone reportedly targeted insurgent hideouts in the troubled region where US troops are conducting a major operation against militants, Reuters reported.

The missiles were fired into an area controlled by Pakistani militant leader Baitullah Mehsud, according to local intelligence officials.

More than fifty insurgents and some Pakistani soldiers have been killed over the last 24 hours in northwestern Pakistan.

US drones have escalated missile strikes in Pakistan since the middle of last year.

The airstrikes are said to be aimed at militants, but Pakistani media say only one in six have target pro-Taliban insurgents in the country.

Hundreds of Pakistani civilians as well as militants have lost their lives in such attacks, which started under the Bush administration in 2006.

JR/MD