Suspected US drones fired missiles at a house and car in a militant-dominated tribal region near the Afghan border, killing at least four people.
The Sunday attack occurred in the Datta Khel area of North Waziristan, two intelligence officials said.
The drones fired three missiles, they added, speaking on condition of anonymity because they were not authorized to talk to the media.
The identities of those killed were not known, though the region is dominated by the Taliban's Haqqani network, which is blamed for launching attacks across the border against American and NATO forces in Afghanistan.
Separately, the bullet-riddled bodies of four Pakistani tribesmen, killed for allegedly spying for the United States, were found Sunday elsewhere in North Waziristan, witnesses and officials said. Officials said the four dead tribesmen were kidnapped by the Taliban about 10 days ago.
Gul Akber Khan, who lives in the village of Srakhula, just outside of Mir Ali, said he heard gunshots in the middle of the night. When he went to the mosque for morning prayers a few hours later, he found the bodies dumped along the road in Miran Shah, the main city in North Waziristan.
Intelligence officials, also speaking on condition of anonymity, said a note was found by one of the bodies. It warned in Pashto: "Spies are spies, and they will come to the same fate as these men ... Do not spy for America."
The tribal regions along the Pakistan-Afghanistan border, strongholds for al-Qaida and Taliban fighters, have seen bloody fighting and regular attacks by American drone aircraft as the Pakistani and US governments try to defeat Islamist militants. Violence also flared in other tribal areas Sunday with helicopter gunships pounding Taliban hide-outs in the Kurram and Upper Orakzai tribal regions, killing 28 militants.
Kurram official Rasheed Khan said 16 died in that region, while Upper Orakzai official Shabbir Gul said 12 died there.
Meanwhile, in Pakistan's southwestern province of Baluchistan, where authorities have been fighting an ethnic insurgency for years, a bomb blast killed at least three people and injured 12 more.
The bomb, planted on a bicycle in Quetta, the capital of Baluchistan, exploded as a police van drove past. It killed two policemen and one civilian, hospital officials said.
Hamid Shakil, a senior police official, said it was apparently triggered by remote control. He blamed the attack on Baluchi nationalists - a militant movement distinct from the Taliban insurgency.