Two missile attacks launched from remotely piloted American aircraft killed up to 21 people in western Pakistan on Friday. The strikes suggested that the use of drones to kill militants within Pakistan's borders would continue under President Obama. A senior Pakistani security official said four of those killed were Arabs. Pakistani intelligence officials often take the presence of foreign fighters as an indication of Al-Qaeda involvement. The first destroyed the house of a man identified as Khalil Dawar and killed eight people in Mir Ali village in North Waziristan late in the afternoon. Pakistani officials said militants later surrounded the area and retrieved the bodies. In the second attack, which came hours later, missiles struck a house near the village of Wana in South Waziristan, killing at least seven people, according to local accounts and Pakistani news reports. The reports said three of the dead were children. American and Pakistani officials are known to share some intelligence about militants, but it is unclear whether Pakistani officials have in any way acquiesced to the drone strikes or helped provide intelligence for them while opposing them in public. Openly supporting the attacks would be untenable for a government perceived as being too close to the American government. The United States does not acknowledges firing the missiles, which are believed to be mostly fired from drones operated by the CIA and launched from neighboring Afghanistan. According to an AP tally based on accounts from Pakistani security officials, at least 263 people _ most of them alleged militants - have been killed in the strikes since last August. But some of the attacks have also killed civilians, enraging Pakistanis and making it harder for the country's shaky government to win support for its own military operations against Taleban guerrillas in the country's lawless border region. Pakistan's government has little control over the border region, which is considered a likely hiding place for Al-Qaeda chief Osama Bin Laden and other terrorist leaders. American officials in Washington said there were no immediate signs that the strikes on Friday had killed any senior Qaeda leaders. They said the attacks had dispelled for the moment any notion that Obama would rein in the Predator attacks. Obama and his top national security aides are likely in the coming days to review other counterterrorism measures put in place by the Bush administration, American officials said. These include orders President Bush secretly approved in July that for the first time allowed American Special Operations forces to carry out ground raids in Pakistan without the approval of the Pakistani government.