KABUL - U.S. air raids on the Afghan capital, Kabul, paused through the night but persisted apace on the southern Taliban stronghold of Kandahar Tuesday, witnesses and reports from Kandahar said.

In the north of the country opposition forces vowed to launch an offensive to seize the town of Mazar-i-Sharif, which lies on a supply route to Kabul and has an air field.

Other than brief anxiety soon after the nightly curfew took effect when what sounded like a helicopter was heard overhead, Kabul residents said they were able to sleep through the night without the fierce staccato explosions of bombs that have rocked the city for several nights.

However, planes roared over southern Kandahar, powerbase of Taliban supreme leader Mullah Mohammad Omar, on the 24th day of U.S. raids, CNN reported. The jets could be heard bombing west of the city, apparently hitting installations of the Taliban militia, CNN said.

The planes also attacked eastern Paktya province, near the town of Sharana, wounding one Taliban fighter, and killing one fighter in nearby Kunduz, the private Pakistan-based Afghan Islamic Press (AIP) said.

The attacks killed four civilians and wounded 10 in Kandahar, AIP said. The reports could not be independently confirmed.

The relentless war on the Taliban to flush Saudi-born militant Osama bin Laden from his Afghan hideout has produced few clear results and may be moving into a new phase in which U.S. commandos open an Afghan ground base to attack their stubborn foes, Pentagon sources said in Washington.

Bin Laden is the prime suspect in the Sept. 11 attacks on the United States in which about 5,000 people were killed.

There was every sign from U.S. officials the raids on Afghanistan would persist into the holy Muslim fasting month of Ramadan, which begins on about Nov. 17.

In neighboring Pakistan, the future of a post-Taliban Afghanistan was under discussion with United Nations envoy for Afghanistan, Lakhdar Brahimi, meeting senior Pakistanis and foreign diplomats as he began seeking out ideas on forming a broad-based government in Kabul.

There was no sign he would meet the Taliban ambassador. The Taliban have refused any contact with U.N. peacemakers since U.N. sanctions were imposed in January.

On the ground the Taliban have given up little territory to the disparate Northern Alliance, a grouping of warlords, mujahideen veterans of the Soviet war and various ethnic minorities, officials of both sides have said.

Fighters loyal to warlord Ismail Khan said Monday they had repulsed a Taliban counter-attack from around the western town of Qala Nau. They said they had cut a key Taliban supply route to the nearby ancient city of Herat - powerbase of Khan until the Taliban toppled him in 1995.

Herat airport was hit by U.S. raids overnight, AIP said.

Both sides claim gains and then admit losses almost daily in the ebb and flow on the battlefield.

But with the opposition still holding less then 10 percent of Afghanistan there was little sign the Northern Alliance, or United Front, was making substantial headway.

A spokesman for Khan said the warlord hoped to advance from a base about 15 miles from Herat in a bid to take the town. The spokesman predicted fierce fighting, but said Khan was trying to win over Taliban troops in talks.

The opposition have said repeatedly Taliban commanders have defected or plan to switch sides, but the reports have been impossible to verify. Aid workers running operations in central Afghanistan have said they see no sign the Taliban is crumbling.

In a sign of the opposition desire to capitalize on any weakness in the Taliban created by U.S. raids, which have focused on front-line positions north of Kabul and around the northern city of Mazar-i-Sharif, top commanders gathered at the weekend for a strategy session, officials said.

Ethnic Uzbek warlord Abdul Rashid Dostum, Ustad Atta, once military aide of the mujahideen government and Shiite Muslim leader Ustad Muhakik met in Dara-i-Suf in northern Samangan province to plans a multi-pronged offensive after weeks of watching U.S. raids, Northern Alliance spokesman Mohammad Habeel told Reuters late Monday.

Their plan is to make for Mazar-i-Sharif, which lies astride vital supply routes to Kabul and has a strategic air field.

``God willing, the offensive will be launched in the very near future,'' Habeel told Reuters by satellite telephone.

The two forces have been locked in a virtual standoff for several weeks outside Mazar-i-Sharif and alliance leaders have called on the United States to intensify raids to break the stalemate.

They also want more bombing of front-line positions north of Kabul, but the United States and its allies do not want an Alliance entry into the capital.

U.S. planes have been bombing Taliban lines north of Kabul watched by opposition forces but there is no sign of a push on the city. The opposition have said they will wait outside the city gates, although many military analysts doubt they have the military capability to advance.

U.S. raids Monday hit an area of caves and tunnels in eastern Afghanistan known as a hideout of Osama bin Laden and killed two people, AIP said.