KABUL (REUTERS) — U.S. planes once again pounded targets outside Afghanistan’s capital Kabul early Tuesday after Washington launched its heaviest daylight strikes so far to root out Osama bin Laden and punish his Taliban protectors.

As a low-flying Air Force Special Forces AC-130 gunship concentrated its fire on targets in the Taliban stronghold of Kandahar Monday, the Taliban’s civil war foes said they were closing in on the key northern town of Mazar-i-Sharif.

CNN quoted witnesses in Kandahar as reporting unusual air activity overnight.

There was no independent confirmation of the report.

Two warplanes screamed over Kabul around 3 a.m. Tuesday, dropping at least three bombs on targets just outside the city in the first attack since late Monday evening.

“The first plane came two minutes ago and attacked with two bombs. The Taliban were firing anti-aircraft fire,” one witness said. “Now there’s another jet — I heard another explosion.”

It was the ninth successive night of attacks to force the Taliban to hand over Saudi-born bin Laden, the man Washington accuses of masterminding the Sept. 11 suicide hijack attacks that killed more than 5,000 people in the United States.

Defense officials in the United States said U.S. planes stepped up daylight strikes Sunday. Monday’s day strikes were the heaviest so far of the military offensive that the U.S. and Britain launched Oct. 7.

The AC-130s, four-engine turbo-prop planes that can carry a crew of 14, including five gunners, could lay down “withering fire,” one official said.

In Kabul, bombs or missiles struck city suburbs, the airport and abandoned military bases to the north, sending residents fleeing from their homes. Defense

Secretary Donald Rumsfeld said Taliban troop concentrations north of Kabul were also targeted.

DEATH TOLL

Air strikes on the capital continued after sunset, with the city in darkness after bombs cut power cables to a main substation north of the city.

“They were very strong and frightening explosions,” one witness said. “I could hear just two to three bursts of anti-aircraft fire from Taliban fighters.”

The Taliban say the military campaign has killed more than 300 people, many of them civilians.

In Washington, Rumsfeld said a Taliban report that 200 civilians had been killed in Khorum village near the eastern city of Jalalabad was “ridiculous.”

Foreign reporters visited the area on Sunday, but while they saw evident destruction and fresh graves, it was not possible to verify the death toll.

Pentagon officials said they had targeted caves and hit two tunnels near the village that were believed to store ammunition, sparking large secondary explosions.

“They were not cooking cookies inside those tunnels,” Rumsfeld said, adding people in the area were probably connected to the activities in the tunnels.

The Taliban’s Northern Alliance civil war foes said Monday that they had advanced to within four miles of the airport in the northern Taliban-held city of Mazar-i-Sharif.

This weekend, Alliance warlord General Abdul Rashid Dostum said he was preparing an offensive on the city that was his headquarters until Taliban captured it in 1998.

The alliance says its forces have taken two towns.

With casualties and hardship growing, Afghans fleeing the conflict for the safety of neighboring Pakistan say the U.S. onslaught is shifting public opinion in favor of the Taliban.