Pakistan intelligence officials say U.S. drone-fired missiles have killed three suspected militants near the Afghan border.

They say the missiles hit a vehicle Monday in the South Waziristan tribal region, known to be the home of al-Qaida and Taliban insurgents.

The U.S. routinely stages drone attacks into Pakistan, but does not publicly acknowledge the program.

The attacks are a source of tension between the U.S. and Pakistan. Islamabad says the missile strikes fuel militancy in the region.