Informant says he can help US find bin Laden

A man linked to the al-Qa'ida network has approached the United States with what he claims is "detailed information" on the whereabouts of Osama bin Laden.

The informant's identity and nationality are being kept secret while he is questioned by CIA and military intelligence officials at an American base in Kandahar. He has told them he is interested in a $25m (£17m) reward offered by Washington for information that would help track down Mr bin Laden, diplomatic sources said.

Lieutenant James Jarvis, a spokesman for the American forces, said: "Our intelligence [agencies] are jumping with joy over the opportunity to question him."

The man is believed to have approached the Americans himself because he did not trust the warlords, who run the Kandahar region with American backing. The governor, Gul Agha Shirzai, recently released seven senior Taliban members who surrendered even though he had been expected to hand them over to the Americans.

Last night, the third batch of detainees in less than a week left Kandahar for the US Navy base at Guantanamo Bay in Cuba, where they will be interrogated. One of the 30 prisoners was sedated.

The Kandahar base remained on alert yesterday after a US Marines patrol spotted men armed with assault rifles and rocket-propelled grenade launchers heading towards an abandoned mud house outside the perimeter. A search discovered rockets, mortar rounds and tunnels. The same area was used by gunmen last week to launch an attack when a C-17 transport plane was taking off with the first batch of 20 prisoners for Guantanamo Bay.

A Marines sergeant, Ethan Ramsey, said troops on the perimeter frequently spotted suspicious figures. "They act like sheep herders, but these sheep herders carry radios and call stuff in," he said. "The weird part of it is, they can just appear in an instant. There's got to be tunnels."

Amid concerns about the danger posed by al-Qa'ida members still in Afghanistan, Donald Rumsfeld, the US Defence Secretary, defended his decision not to send in a large ground force to find Mr bin Laden when al-Qa'ida fighters made a final stand at the Tora Bora cave complex last month.

"The larger number of Americans on the ground might very well have hastened his departure as opposed to delayed it," Mr Rumsfeld said. "Had we had a lot of people on the ground ... you would have gotten everyone in Afghanistan against you, as opposed to just the Taliban and al-Qa'ida."

Refugees denied the presence of al-Qai'da members in Zhawar, near Pakistan, where US planes have been bombing suspected terrorist bases this week. They said a few Taliban fighters loyal to a senior local figure, Jalaluddin Haqqani, had all dispersed. One villager, Shah Zaman, 35, said his home had been destroyedand repeated claims by other refugees that 15 civilians had been killed. He said a relative was among five people detained by American troops before being given money and released.

Meanwhile, John Walker Lindh, the captured American aged 20 who fought with the Taliban, will be charged with conspiracy to kill US citizens. He could face life in prison if convicted. The authorities had been considering treason charges after he was found among Taliban prisoners in the northern city of Mazar-i-Sharif. The crime of treason carries a death sentence. John Ashcroft, the Attorney General, said: "He chose to embrace fanatics, and his allegiance to those terrorists never faltered."

A group of Americans who lost relations in the 11 September attacks held meetings yesterday with Afghan families who suffered in the US bombing. Abdul Mohammed, 26, who lost five relatives to a bomb, said he had hoped the visitors would bring offers of compensation, but that did not happen.

Also yesterday, Kabul's airport re-opened after repairs. It may be used by Colin Powell, the Secretary of State, when he arrives for a visit today.