Sun Oct 26, 2008 6:23pm EDT

PESHAWAR, Pakistan (Reuters) -

A suspected U.S. drone fired missiles on Monday into a Pakistani region on the Afghan border that is a stronghold of a Pakistani Taliban leader, killing up to 20 people, intelligence officials said.

Suspected U.S. drones have carried out more than a dozen such missile attacks on (alleged Taliban targets) on the Pakistani side of its border with Afghanistan since the beginning of September, killing dozens of people.

"Two missiles were fired, they hit two houses in Shakai and up to 20 people were killed," said one of the Pakistani intelligence agency officials, referring to an area in the South Waziristan region that is a stronghold of Pakistani Taliban leader Baitullah Mehsud.

The intelligence agency officials, who declined to be identified, had no details about the identity of (those who were killed) in the houses hit by the missiles.

The Pentagon said it had no information on the drone strike.

U.S. forces in Afghanistan, frustrated over growing cross-border attacks from the Pakistani side of the border, have stepped up their attacks into Pakistan with missile strikes and a commando raid since the beginning of September.

No senior al Qaeda or Taliban commanders have been reported to have been killed.

Pakistan objects to the U.S. strikes on its territory saying they violate its sovereignty and increase support for the militants.

(Reporting by Alamgir Bitani and Haziz Wazir; Writing by Zeeshan Haider; Editing by Robert Birsel and Jon Boyle)