Updated

The U.S. Air Force increased its bombing of Taliban and other insurgent targets in Afghanistan this spring, making about 750 airstrikes in May alone, Air Force officials said.

The intensified bombing in Afghanistan has overshadowed the smaller number of U.S. airstrikes on Iraq, said Air Force Lt. Gen. Gary L. North, who commands U.S. and coalition air operations in Iraq and Afghanistan.

"We have seen more direct support in Afghanistan that is of a kinetic effect than in Iraq of late," North told The Associated Press during a visit Monday to the United Arab Emirates, where he met with defense officials.

CountryWatch: Afghanistan

Insurgents have mounted a spring offensive against the deployment of U.S.-led troops in the southern Afghan provinces of Helmand and Kandahar, drawing intense bombardments from American warplanes. The surge in fighting has killed more than 400 people, mainly militants, since mid-May.

"As always in the spring, the insurgents are coming out and trying to destabilize" the Afghan government, said North, 52, of Charlottesville, Va.

On May 21, the U.S. bombing of Azizi village in Kandahar province killed at least 16 civilians, along with dozens of militants hiding in the compound. Human rights monitors said as many as 34 civilians died in the strike.

North, who also commands the U.S. 9th Air Force, described the civilian deaths as "regrettable" and said they were being investigated.

"What went wrong to best of my knowledge, is the Taliban were retreating and firing on coalition forces and took cover in a facility in which civilians were present. Apparently they used the civilians as human shields," North said. "When you've got enemy forces hiding with civilians, it's problematic."

The increased U.S. bombing has sparked opposition from Afghans angered at the rising death toll of civilians, which Afghan lawmakers blame for a surge in Taliban support.

Afghan President Hamid Karzai took the unusual step last month of summoning the top U.S. commander in Afghanistan, Lt. Gen. Karl W. Eikenberry, and telling him "every effort" should be made to ensure civilians' safety.

Karzai has often called for investigations into civilian deaths and has repeatedly asked the coalition to take care in their bombing targets. Last September he said airstrikes were no longer effective, but that was before the recent surge in rebel attacks.

In 2004, the U.S. military modified its rules of engagement after Karzai expressed outrage over the deaths of 15 children in two airstrikes in late 2003.

U.S. warplanes logged nearly 2,000 strikes in Afghanistan between March and May 2006, about as many as the same period in 2005, said Air Force Maj. Michael Young. But airstrikes spiked at 750 this May, as opposed to 660 in May 2005, Young said.

In Iraq, North said U.S. warplanes weren't cutting back on sorties, but fewer bombs were being dropped. Recent U.S. bombing has concentrated on the rebel stronghold of Ramadi, a Sunni Muslim city west of Baghdad where U.S. Marines are embroiled in a counter-insurgency battle.

"Ramadi is currently where the insurgents are making a play. So there are more operations in that area," North said.

In Afghanistan, much of the bombing has been done by U.S. B-1B Lancer bombers that on May 1 replaced an outgoing fleet of the Air Force's aging B-52s. North said the air raids were being called for by ground commanders seeking close air support — which includes bombing, strafing or other raids — and that B-1s and Air Force A-10 ground attack jets were flying most of the sorties. The raids are concentrated in remote battlefields in southern and eastern Afghanistan.

"We've been called on in Afghanistan to have a wide range of effects, and we have been dropping bombs in support of the ground component commander and the Afghan national army. We've been having very good success."

The increase in airstrikes, North said, was partly due to insurgent maneuvers that exposed their positions.