An international force began its mission in the Afghan capital Kabul today on the eve of the installation of a new government with the mammoth task of rebuilding the country after two decades of war.
But as the campaign that toppled Afghanistan's fundamentalist Muslim Taliban rulers moved into a new phase, the manhunt intensified for Saudi-born Osama bin Laden, the man that they sheltered in defiance of the international community.
US agents interrogated captured fighters from bin Laden's al Qaeda network for clues in the search for the man accused of masterminding the September 11 attacks that killed almost 3,300 Americans and other nationals in the United States.
In Washington, President Bush said much had been accomplished in the first 100 days of the US-led campaign against terrorism.
"We've built a broad international coalition against terror," he said. "We broke the Taliban's grip on Afghanistan. We took the war to the al Qaeda terrorists. We're securing our airways. We're defending our homeland. And we're attacking the terrorists' international financial network."
Defense officials said the US military was considering a plan for hundreds of Marines and Army troops to search Afghan caves and tunnels for al Qaeda guerrilla leaders.
Mr Bush also announced action to block the assets of two groups he said had links to terrorism.
India accuses one of the two, the Pakistan-based Kashmir separatist group Lashkar-e-Taiba, also known as Army of the Righteous, of launching a December 13 suicide attack on its parliament.
Mr Bush said the other group, Umma Tameer-e-Nau, was established by a former Pakistan atomic energy commission official and masqueraded as a charity for the hungry in Afghanistan.
In reality, he added, the group gave nuclear weapons information to bin Laden's al Qaeda network.
At Bagram Airbase outside Kabul, 53 British Royal Marines landed yesterday to take up a security role in the capital ahead of Saturday's installation of an interim government.
Britain is leading the international force, which is intended to nurture the country's fragile peace. The force received a UN Security Council mandate on Thursday.
"We will be assisting with the running and providing a presence at the inauguration of the interim government," Company commander Major Matt Jones told reporters on arrival in Kabul.
Afghan factions agreed in Bonn to set up a six-month interim government to replace the Taliban, routed by their local opponents backed by weeks of US air strikes. Part of the deal is the dispatch of a multinational security force.
Mr Jones said the mission would begin today when his men, accompanied by Afghan security forces, would accompany VIPs arriving for the ceremony from Bagram Airbase to Kabul.
In a softly-softly approach to the citizens of war-torn Kabul, Mr Jones said the troops would be keeping a low profile. They would wear berets, not helmets, ride in unarmored Land Rovers and would carry only light arms.
"Afghanistan particularly, probably has a sensitivity to foreign troops. We have no reason to upset anyone," he said.
But residents of Kabul also have bitter memories of the last time the Northern Alliance, the militarily dominant anti-Taliban faction, held power in the city from 1992 to 1996.
Memories of the carnage as its rule collapsed into factional fighting have swelled support among ordinary Afghans for the presence of foreign troops.