WASHINGTON

WASHINGTON (CNN) -- U.S. warplanes pounded Afghanistan's southern city of Kandahar on Sunday after the ruling Taliban's spiritual leader rejected a new call to turn over suspected terrorist leader Osama bin Laden.

The latest U.S. raids on Kandahar lasted for several hours, focusing on Taliban military headquarters and power lines, sources told CNN.

Raids also targeted the Afghan capital of Kabul, but not as intensely. As darkness fell, U.S. air attacks on Taliban positions about 40 miles north of Kabul resumed for an eighth day.

Mullah Mohammed Omar, the Taliban's supreme leader, issued a defiant statement Saturday, urging the world's Muslim community to be "with Islam, not with Bush. With truth, not lies."

"You, the Muslims of the world, who are watching with your own eyes live pictures of atrocities on your Muslim brothers, and you don't make a move?" Omar said. "Are some of you on the side of the infidels, or are you with us?"

The United States wants the Taliban to hand over bin Laden -- the man U.S. officials hold responsible for the September 11 attacks on New York and Washington -- and other leaders of his al Qaeda organization. President Bush repeated that call Thursday, telling reporters in Washington he would rethink the U.S. attacks on Afghanistan if the Taliban delivered bin Laden.

But in a statement distributed Saturday by the Afghan Islamic Press agency, Omar said, "We have not agreed with America to hand over anyone.

"They have accused Osama bin Laden of these incidents, but they have not presented us with any convincing proof," Omar said.

Also Sunday, bin Laden's al-Qaeda organization has released a videotaped statement calling the first wave of U.S.-led strikes against Afghanistan "vicious." The Bush administration dismissed the statement as "just more propaganda."

With what could be a long war against terrorism entering its second week, U.S. officials have said the airstrikes have been effective overall. In his Saturday radio address, Bush said the goals of "the first phase of our campaign" had been achieved.

"We have disrupted the terrorist network inside Afghanistan. We have weakened the Taliban's military. And we have crippled the Taliban's air defenses," he said. "American forces dominate the skies over Afghanistan, and we will use that dominance to make sure terrorists can no longer freely use Afghanistan as a base of operations."

During the first week of strikes, U.S. operations have been aimed at the ruling Taliban's defensive infrastructure, units on the ground and underground bunkers used by the Taliban and al Qaeda.

On Friday, Defense Secretary Donald Rumsfeld said the Taliban and al Qaeda communications and air defense capabilities have been disrupted, "and we have worked over a number if not all of their terrorist training camps."

"We know that we have found some concentration of Taliban and al Qaeda forces, and we know that they are moving -- that their life is more difficult, and the places where they have stayed, some of them have disappeared," Rumsfeld said.