Striking at the last centre of Taliban power, US Marines have landed outside the southern city of Kandahar in the first deployment of a sizeable US ground force in Afghanistan. The Northern Alliance said its troops were "cleaning out" pockets of resistance in the newly fallen city of Kunduz.

Officials were still trying to count the dead in a bloody uprising by captured fighters for Osama bin Laden and the Taliban. Planes circled above the fortress outside the northern city of Mazar–e–Sharif where the insurrection – which was partly quelled by US airstrikes – had erupted a day earlier.

The deployment of American Marines near Kandahar marks a perilous new phase of a conflict that until now has been focused on US airstrikes targeting urban infrastructure and backing up the opposition Northern Alliance – plus limited ground missions by several hundred American special forces fanned out in small units across Afghanistan.

Kandahar, the Taliban's home base and spiritual center, has come under fierce bombardment since the US–led military campaign began Oct. 7, and the Taliban have vowed to fight to the death rather than abandon the city. In the last three weeks, they have lost their grip on three–quarters of Afghanistan, plus the capital, Kabul.

Heavy explosions rocked the area around Kandahar overnight and early Monday, with bright flares illuminating the night sky, a witness in the city said.

Most of the top Taliban leadership is believed to be holed up in and around Kandahar. Efforts by tribal leaders to negotiate a handover of the city have failed to yield results.

The initial force of Marines, numbering in the "low hundreds," was to be followed by several hundred more from Navy ships in the Arabian Sea, a US official said in Washington, on condition of anonymity. The Marines landed by helicopter southwest of the city, the official said.

Word of the fall of Kunduz in northern Afghanistan came from the Northern Alliance, whose troops were trying Monday to consolidate their hold on the city. Militant holdouts were believed to still pose a serious threat to the alliance forces, who first entered Kunduz Sunday.

Pro–Taliban fighters fled toward the town of Chardara, to the west, with alliance troops in pursuit, alliance acting foreign minister, Abdullah, said by satellite telephone from the north of Afghanistan. Thousands of others have surrendered over the past two days.

The alliance acknowledges that pockets of resistance remain in Kunduz – particularly from hard–core Taliban from Kandahar and from foreign fighters loyal to bin Laden.

"Our forces ... are meeting some obstacles and some resistance, mostly from the foreign Taliban," Abdul Vadud, the military attache at the Afghan embassy in neighboring Tajikistan, said Monday after speaking by satellite telephone with several field commanders.

"Our forces are cleaning out neighborhoods of Taliban," he said, adding that defenders were surrendering their weapons, but "only gradually."

The foreign fighters still inside Kunduz are comrades of the captured fighters who staged Sunday's uprising outside Mazar–e–Sharif. In it, the prisoners – about 300 Chechens, Pakistanis and Arabs who surrendered Saturday from Kunduz – seized weapons and used smuggled ones to try to fight their way out of the fortress.

The Alliance said most of the prisoners were killed.

Yahsaw, a spokesman for northern alliance commander Mohammed Mohaqik, said the prisoners broke down the doors and tried to escape. As outnumbered guards perched on the compound's walls fired wildly down at the prisoners, a US special forces soldier could be seen in German TV footage, using a phone to call in airstrikes and reinforcements.

The captives appeared to have planned the battle, Central Command spokesman Lt. Cmdr. Dave Culler said, describing it as an apparent "suicide mission."

In other developments:

– In Herat, Northern Alliance commander Mohammed Zaer Azimi said Taliban leaders were discussing the possibility of Kandahar's surrender, but offered no details. He also said alliance forces were preparing for a major attack on Helmand, another Taliban stronghold in the south. But it is unclear whether the alliance has enough men and heavy weapons to press an offensive in the south.

– Representatives of three key Afghan groups left for Germany to attend a U.N.–sponsored meeting aimed at forming a broad–based government in war–torn Afghanistan. One delegate, Syed Hamid Gailani, expressed doubts the conference would succeed because the factions are not sending their top leaders.