The convergence of U.S. and Pakistani interests in the South Waziristan tribal region suggests the two uneasy allies were cooperating in the strikes, making it harder for Islamabad to protest them publicly as it has in the past.
The army denied signing off on the attacks and insisted they were hurting its campaign against Pakistani Taliban chief Baitullah Mehsud by alienating local tribes it is trying to enlist in the fight.
Meanwhile, an army spokesman said a Pakistani jet attack wounded the local Taliban commander in the scenic Swat Valley elsewhere in the northwest. Troops have been battling militants in Swat for more than two months, an offensive that has so far failed to net any top insurgent leaders.
The mountainous border region is home to al Qaeda and Taliban leaders who plot attacks in Pakistan and neighboring Afghanistan, which is witnessing an unprecedented level of violence against U.S. and NATO troops.
South Waziristan is the stronghold of Mehsud and his followers, whom the government blames for more than 90 percent of the suicide bombings in Pakistan in recent years. The U.S. State Department says Mehsud is a key al Qaeda facilitator in the region.
Suspected American drones have carried out more than 45 attacks in the region since last August. Although most have targeted foreign al Qaeda militants and those accused of violence in Afghanistan, increasingly they are aimed at the Mehsud network.
The first strike Wednesday took place before dawn. Six missiles were fired at a mountaintop training camp in the Karwan Manza area of South Waziristan, killing 10 militants, Pakistani intelligence officials said on condition of anonymity because they were not authorized to speak to media.
Hours later, 12 miles to the east, missiles hit four vehicles carrying Taliban militants, killing at least 35, including a key Taliban commander, one intelligence official said. Another said 50 were killed.
Independent verification of the targets and casualties was not possible because the region is remote, dangerous and largely inaccessible to journalists. U.S. and Pakistani officials do not publicly comment on such strikes.
On Tuesday, a suspected U.S. missile attack killed 12 militants in South Waziristan, including five foreigners, according to intelligence officials. Another recent strike killed up to 80 insurgents attending a funeral.
The timing is significant because Pakistan's military is also carrying out bombing runs and firing mortar rounds at militant targets in the region as part of efforts to kill or capture Mehsud and his followers. It says it plans to launch a large offensive there soon.
The government routinely protests suspected U.S. missile strikes as violations of Pakistani sovereignty and has publicly asked the U.S. to give it technology to launch its own attacks. But many analysts suspect the government which has received billions of dollars a year from the U.S. since 2001 supports the strikes, especially those against Mehsud and his Tehrik-e-Taliban Pakistan.
"They are decrying them on one hand and aiding and abetting them on the other," said Shuja Nawaz, director of the U.S.-based Atlantic Council. "It is helpful for the Pakistanis when the TTP is being targeted. There is obviously much better coordination now."
Speaking after Tuesday's attack, Maj. Gen. Athar Abbas insisted the U.S. help was unwelcome and alienated local tribes it wanted to enlist in the fight against Mehsud.
The United States has been trying to get Pakistan's military to crack down on militants in the border area since the Sept. 11, 2001 attacks, but the country's past nurturing of militants to use as proxies in Afghanistan and Pakistan has complicated those efforts.
The Swat offensive began after militants there violated a peace deal with the government and moved into regions close to the capital, Islamabad. The army claims to have nearly cleared the valley of insurgents, killing more than 1,500.
Abbas told a news conference Wednesday that according to "credible information," the leader of the Swat Taliban, Maulana Fazlullah, was wounded in a recent airstrike. Fazlullah's capture or killing would be a major symbolic victory for the army and could ease the fears of some 2 million residents who fled the valley and surrounding districts and have yet to return.