Pakistani intelligence officials say at least four people have been killed in a suspected U.S. drone strike in the militant stronghold of North Waziristan.
Officials say missiles hit a house and a vehicle near Miranshah, Friday. The region is near Pakistan's border with Afghanistan.
The attack comes a day after President Asif Ali Zardari warned that U.S. drone strikes were undermining Pakistan's "national consensus" in his country's war against militants. However, visiting U.S. lawmakers told Pakistani officials the U.S. could not afford to abandon the controversial missile strikes.
Meanwhile, Pakistani officials say at least eight suspected militants have been killed in an explosion at their safehouse in the commercial center of Karachi.
Investigators say the suspected militants accidentally detonated the explosives Friday, destroying the safehouse.
Bomb squads helped search through the rubble. Police say some of the victims are militants and at least two suspects have been arrested.
Officials also recovered guns, grenades, suicide vests and other explosives from the scene.
Interior Minister Rehman Malik says some of the men in the house were from the country's Swat Valley. Pakistan's military launched a massive offensive there last April to drive out the Taliban, causing millions of people to flee their homes.
Elsewhere, Pakistani officials say at least five people have been killed in a suicide bombing in the northwestern Khyber district.
Investigators say the bomber targeted members of a rival Islamist extremist group. Officials say the bomber blew himself up after a security guard stopped him outside a building belonging to Ansarul-Islam.
Ansarul-Islam has long clashed with another militant group in the region, called Lashkar-e-Islam.
Some information for this report was provided by AP.