The bombing is some of the heaviest so far
Wave after wave of B-52 planes carried out the attacks - which, for a time, came every 30 minutes.
The area has a network of tunnels and caves, in which Bin Laden is widely believed to have been hiding.
There has as yet been no official sighting of the Saudi-born fugitive, but one unconfirmed report says he has taken personal command of his al-Qaeda force battling anti-Taleban troops in forests close to the cave complex.
Extradition demand
US Vice President Dick Cheney said on Sunday that if Bin Laden and Taleban spiritual leader Mullah Mohammed Omar were captured by other forces, they should be handed over to the US to face trial.
In an interview on NBC's Meet the Press, Mr Cheney said the two leaders were exactly the sort of people who would be tried by closed military courts.
He defended the courts, saying extremists had used previous open trials to learn new ways to attack the US.
Mr Cheney said US forces would remain in Afghanistan to help with humanitarian relief and would support any international peacekeeping force.
Fighting back
Reports say that, despite the intense US bombing and shelling by Northern Alliance tanks, al-Qaeda fighters are putting up stiff resistance.
"Osama has taken command of the fighting," Northern Alliance spokesman Mohammad Amin told Reuters news agency, adding that Bin Laden and about 1,000 fighters had "dug themselves into" the forests of nearby Spin Ghar.
US marines have been scouring the area around the city of Kandahar in southern Afghanistan, carrying photographs of key members of al- Qaeda.
On Saturday, Pakistan said it had increased surveillance of its 2,500km (1,500 mile) border with Afghanistan to try to prevent the escape of al-Qaeda members.
A Pakistani military spokesman said hundreds of soldiers had been deployed at key points along the border, and armed helicopters were patrolling the area.
Possible escape
From the outset of its military campaign, the US has made it clear that its primary objective is to hunt down Bin Laden and bring him to justice.
All possible escape routes from Afghanistan are being patrolled by helicopters, military vehicles and foot patrols.
But senior US officials acknowledge that America's most wanted man may already have slipped across the border.
"We are looking for him in Afghanistan, we are looking for him out of Afghanistan, including at sea," said US Deputy Defence Secretary Paul Wolfowitz.
He specifically cited Pakistan, Somalia and Yemen as countries where Bin Laden might try to seek refuge.
A Pakistani military spokesman, Major-General Rashid Qureshi, has insisted that neither Bin Laden nor Taleban leader Mullah Omar have entered Pakistan - and they would be arrested if they did.