Attacks in Pakistan's southern Shaktoi area have become a source of friction between the U.S. and Pakistan, which sees them as a violation of its sovereignty
Pakistani officials say a suspected U.S. drone missile strike has killed at least 20 militants. Authorities say the toll could rise.
Sunday's attack took place in the Shaktoi area of Pakistan's restive South Waziristan region.
Saturday, Pakistani Taliban militants issued a new audio recording they said proved their leader, Hakimullah Mehsud, survived a suspected U.S. missile strike last week.
Pakistani intelligence sources had said Mehsud was wounded in the missile strike that killed at least 12 suspected militants Thursday.
The United States has increased attacks using drones since a suicide bomber killed seven U.S. intelligence agents in eastern Afghanistan in late December.
Some information for this report was provided by AFP and Reuters.