Alliance fighters bury one of their dead near Taloqan
The Northern Alliance has driven the Taleban out of another key city, Taloqan, its former headquarters and an economic centre.
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The move could cut off Taleban forces in north-eastern Afghanistan.
There is no independent confirmation of this, but Taleban officials said their lines had come under heavy US bombardment and they had made a tactical withdrawal from three northern provinces.
A journalist who entered Taloqan with Alliance troops said hundreds of people came out to greet them.
In other developments:
Journalist killed
A French radio journalist was killed in Afghanistan on Sunday when the Northern Alliance troops she was travelling with fell into a Taleban ambush.
The BBC Kabul correspondent says the Taleban appear to be on the run in most of the north and centre of Afghanistan.
The opposition forces further claim to have seized the strategic town of Pul-e-Khumri, north of Kabul, and the town of Qala-e-Nau in the western province of Badghis.
The capture of Pul-e-Khumri would cut the main north-south road through the centre of Afghanistan, leaving the remaining Taleban forces in the north stranded. The Alliance said Taleban commanders south of Pul-e-Khumri had defected, weakening the garrison in the town of Bamiyan - the Taleban's main base in the central highlands.
The Taleban still control the hills to the north of the capital, above the Bagram airbase.
In the capital, Kabul, Taleban fighters have set up roadblocks.
They told a BBC correspondent in the city that they were searching for possible infiltrators.
Two people were killed in Kabul on Sunday when a marble factory close to a military compound was hit by a US bomb, the official Bakhtar news agency reported.
Push on capital
Since their capture of Mazar-e-Sharif on Friday, the Northern Alliance say their troops have advanced 140 kilometres (90 miles) through Bamiyan and Baghlan provinces in a thrust to join up with frontline forces outside the capital.
But US Defense Secretary Donald Rumsfeld told journalists on Sunday "pockets of resistance" persisted in Mazar-e-Sharif.
Our correspondent says the political future of the Northern Alliance and the success of the American campaign could stand or fall on how Alliance soldiers behave in newly-captured towns like Mazar-e-Sharif.
Kabul warning
US President George W Bush has warned the Afghan opposition against trying to seize control of Kabul because it could endanger hopes for a future broad-based government.
"We don't have enough forces on the ground to stand in their
way," Mr Rumsfeld said.
The Northern Alliance has indicated that it might try to take control of the capital if there were a "political vacuum" although it said it would also prefer a broad political agreement..
Mr Rumsfeld suggested that capturing Kabul was not a primary aim of the United States and its allies.
He said the main targets lay outside the capital - the leadership and fighting forces of Osama bin Laden's al-Qaeda network and the Taleban.
UK Prime Minister Tony Blair said the pace of the opposition advance was being dictated by the Americans.
We would prefer to achieve a broad political agreement ...before moving into Kabul. But we do not commit ourselves to this if there is a political vacuum
Abdullah Abdullah
Northern Alliance Foreign Minister
Northern Alliance Foreign Minister Abdullah Abdullah said 15,000 Taleban troops were trapped in the north-eastern Kunduz province, and Alliance forces were advancing on them.
The journalist, Johanne Sutton, worked for Radio France Internationale. A second journalist who was with her has been reported missing.
People speaking to the BBC by telephone from the city said groups of armed men were roaming the streets and they were concerned that security was deteriorating.
But US Defense Secretary Donald Rumsfeld acknowledged that it might be difficult to stop the Northern Alliance if they tried to seize the capital.
