At least three bombs fell in the Kabul area Monday _ one each in the eastern, western and northern sections of the city, the respective locations of a TV transmission tower, the airport and an abandoned fort. The Afghan Islamic Press agency in Islamabad, Pakistan, said the airport and a hill where the transmitter is located were both targets.

The agency, which has close ties to Afghanistan's ruling Taliban, said one bomb landed near a 400-bed women's hospital in Kabul but made no mention of any damage. The reports could not be independently confirmed because a curfew is in effect in the Afghan capital.

Taliban gunners responded with heavy bursts of anti-aircraft fire. One high-flying plane could be seen dropping flares before the detonations.

The military campaign is aimed at punishing the Taliban for harboring Osama bin Laden, the man accused of masterminding the Sept. 11 attacks on New York and Washington that killed more than 5,000.

Power was cut in Kabul soon after Monday's U.S. barrage began, and Taliban radio ordered people to close their blinds, shut off lights and stay indoors.

Other strikes were under way at the Taliban stronghold of Kandahar, a Taliban official said. Taliban positions around the northern city of Mazar-e-Sharif were also under attack Monday, the Afghan press agency reported. A spokesman for the opposition northern alliance, Ashraf Nadim, said by telephone that U.S. aircraft and missiles were launched against the Taliban.

Nadim was speaking from Samangan province, about 30 miles from Mazar-e-Sharif. He said opposition leaders were tipped off by the United States a half hour before Monday's attacks.

The Afghan Islamic Press agency said the northern alliance launched a major attack Monday evening on the Taliban position near Dara-e-Suf, in northern Samangan.

Britain, which participated in the first wave of assaults on Sunday, did not take part in Monday's follow-up, Prime Minister Tony Blair said from London.

In Washington, Defense Secretary Donald H. Rumsfeld suggested there was much left to do after the first night's aerial assault. "We believe we've made progress toward eliminating the air defense sites," he said. "We believe we've made an impact on military airfields. ... We cannot yet state with certainty we have destroyed" dozens of command and control and other military targets," he said.

Air Force Gen. Richard Myers, chairman of the Joint Chiefs of Staff, said the fresh bombardment _ bombs delivered by 20 warplanes as well as cruise missiles launched from ships _ was accompanied by a renewed air drop of humanitarian assistance.

Before Monday's attacks began, President Bush vowed to be "relentless" in fighting terrorism "on all fronts."

In an indication the United States might want to some day expand the military operation, Washington formally notified the U.N. Security Council on Monday that counterterrorism attacks may be extended beyond Afghanistan.

In addition to Kabul and Kandahar, the first night of strikes Sunday targeted Jalalabad, along the Pakistani border, and Mazar-e-Sharif. The compound of Taliban leader Mullah Mohammed Omar in Kandahar, as well as training bases of bin Laden's al-Qaida network were also hit in the first night's assault.

Taliban radio on Monday derided the previous night's strikes as a failure. "The American bombardment and rocket attacks didn't hit their targets," it said.

Shortly after the first attacks on Sunday, bin Laden vowed in an apparently pre-taped message that America will "never dream of security." He praised God for the Sept. 11 attacks and said the United States "was hit by God in one of its softest spots."

Taliban officials said both he and Omar survived the first night's assault.

Before the night assault Monday, the Taliban released a British journalist and handed her over to Pakistani authorities, border officials said. Yvonne Ridley, a reporter for a London tabloid, had been arrested in Afghanistan 10 days earlier, after all foreigners were ordered out of the country. The militia is still holding eight foreign aid workers _ including two Americans _ accused of trying to convert Muslims to Christianity.

Washington called the airstrikes that began Sunday night a success, saying military installations and terrorist training camps were prime targets. Britain, which took part in the raids, said some of the camps were apparently empty, but that hitting them deprived al-Qaida of some of its bases.

Most of neighboring Pakistan was calm before Monday's new assault, but fierce protests broke out in a pair of border cities where pro-Taliban sentiment runs high. One person was reported killed and more than two dozen hurt in unrest in the southwest Pakistani city of Quetta.

Mobs stoned the Quetta office of the U.N. refugee agency and torched the U.N. children's agency office in the same compound, but no staffers were hurt. Pakistan's government, which supports the mission against the Taliban, expressed regret over the destruction and said security around U.N. installations would be tightened.

Across the Mideast, there was anger at the U.S. counterattack and some support for bin Laden.

In the Gaza Strip, anti-American demonstrations ended with a gunbattle between Palestinian police and student protesters that left two Palestinian bystanders dead and 50 wounded.

A trickle of Afghan witnesses arriving in Pakistan provided accounts of Sunday night's airstrikes, which targeted Kabul, along with the cities of Jalalabad and Kandahar _ the Taliban's home base.

"I was standing on my roof when I heard planes overhead, and the next thing I knew there were explosions and panic everywhere," said a Kandahar man named Nematollah, who like many Afghans uses one name.

The Taliban ambassador to Pakistan, Abdul Salam Zaeef, called the U.S.-led attacks indiscriminate terror against civilians, and said 20 women, children and elderly were killed in Kabul in Sunday's assault.

"The brave people of Afghanistan will never be intimidated by these fears," he told journalists in Islamabad. "By sacrificing their lives, they will defend the faith, Islam."

Many humanitarian officials fear the military assault on the Taliban and bin Laden will worsen already widespread hunger and privation in Afghanistan. The U.N. food agency said Monday it had halted all deliveries of aid inside Afghanistan following the U.S.-led attacks.

The United States hoped to make up some of the shortfall with airdrops from C-17 cargo planes. The first such flights Sunday were termed a success, dropping 37,500 food packages that were designed to flutter to the ground rather than plummeting straight down, to minimize the possibility of injury.