administration's intent to press ahead with a tactic that has killed scores of militants over the last two years but is also raising fresh anger in a nation allied with Washington.
On the ground, it means fear-filled sleepless nights. "We have become used to the drone attacks, but now people are scared as they are coming every night," said Israr Khan Dawar, a 17-year-old student in Mir Ali, a town in the militant-riddled North Waziristan region.
"More noise means they are flying lower, and that means an attack is more likely," he added.
A UN investigator said the surge added to the need for the cloak of secrecy to be lifted from the CIA-run program, which has killed civilians as well as insurgents. Critics say the program does more harm than good because it fans anti-US sentiment and anger at Pakistan's own government.
The drones, piloted remotely from bases in the region or in the United States, are Washington's only known military response to al-Qaida and Taliban militants based in Pakistan's tribal areas along the Afghan border. The insurgents are behind attacks on American, NATO and Afghan troops in Afghanistan and officials say they are also planning attacks on Western targets. In the two weeks beginning Dec. 31, eight drone strikes hit targets in North Waziristan, the most intense volley since the program began, according to a tally by The Associated Press. On Dec. 30, a suicide bomber killed seven CIA employees at an American base in Afghanistan just across the border from North Waziristan.
Many fighters from the Pakistani Taliban, which have claimed responsibility for the CIA attack, have fled to North Waziristan in the past few months to escape an army offensive in neighboring South Waziristan. North Waziristan is also a major stronghold for the Haqqani network, an Afghan Taliban faction with links to al-Qaida that many suspect was also involved in the CIA bombing. The frequency of the drone strikes has increased since mid-2008. Last year, there were at least 45 attacks, compared to 27 in 2008, according to the AP tally.
The attacks killed around 700 people last year, many identified as militants by Pakistani officials interviewed after the attacks. Last weekend, a Jordanian militant who served as a bodyguard for al-Qaida's No. 3 leader is believed to have been killed in one of two strikes close to Mir Ali.
Independent reporting following the attacks is nearly impossible because militants seal the area.
US officials do not normally acknowledge firing the missiles, much less give information on casualties.
UN investigator Philip Alston called on the United States to reveal who was being targeted in the attacks and list the casualties, saying it had an obligation to do so under international law. He contrasted the situation to Afghanistan, where there are investigations into allegations of civilian casualties and guidelines on when bombs could be dropped.
"The whole program is so secretive that we have very little information to evaluate whether the United States is honoring its obligations under the Geneva convention," he said, citing requirements to target only combatants and avoid civilian casualties and other rules of war. "When we were dealing with isolated cases I raised it with the United States. Now that it is systematically using drones, it is becoming increasingly important to get clarification."
Residents in Mir Ali said mostly civilians were being killed in the attacks and urged the government to stop them. But academic Farhat Taj cautioned that people living in the region were unable to speak honestly out of fear of Taliban retribution. She said that based on her discussions with people who have left the area, many support the strikes because they are accurate.
"They are appreciated for their precision and the lack of collateral damage compared to the Pakistani army," said Taj, who is a member of the Islamabad-based Aryana Institute for Regional Research and Advocacy, which studies northwest Pakistan. In public, Pakistani government officials criticize the strikes and say the United States, which is deeply unpopular, is acting unilaterally. But there is little doubt Islamabad agrees to at least some of the attacks. A Pakistani intelligence officer said Pakistani agents provide targeting information on some of the targets. The intelligence officer, who spoke on condition of anonymity, warned against increasing the drone strikes further or expanding them to other parts of the border region.
"There is a limit," he said, saying it is affecting public support for the government's fight against militants.