Missiles fired from US drones on Tuesday killed at least four militants in Pakistan's northwest tribal region near the Afghan border, security officials said.
"Eight missiles were fired from about five US drones on a militant compound in Dattakhel village," a senior security official told AFP.
"At least four militants were killed and the toll is expected to rise," the official said.
A local administration official and two intelligence officials confirmed the missile strike and deaths.
Officials and residents said the missiles struck militants' hideouts and a training centre.
North Waziristan is a known base for insurgents belonging to the Haqqani network, which is blamed for staging attacks on US and NATO troops in Afghanistan.
A volley of drone strikes, which fuel anti-American sentiment in the nuclear-armed Muslim nation, have hit the northwest this month.
A number of US strikes in early January are reported to have targeted Pakistani Taliban leader Hakimullah Mehsud, but he then dispelled rumours of his death in an audio recording, also vowing revenge for the drone programme.