KABUL, Afghanistan (Reuters) - Afghanistan's Taliban rulers did not rule out Tuesday the possibility that Osama bin Laden masterminded the attacks on the World Trade Center and the Pentagon, but needed proof before he could be handed over.

"Anyone who is responsible for this act, Osama or not, we will not side with him," Information Minister Qudrutullah Jamal told Reuters by telephone from Kabul, conceding for the first time that bin Laden may have been involved in last Tuesday's devastating attacks that killed about 5,000 people.

Previously the hard-line Islamic movement has insisted bin Laden could not possibly have been involved. Bin Laden has been reported as denying any role.

Jamal was speaking just hours after high-ranking Pakistani officials flew home after two days of talks aimed at persuading the Taliban that if they do not hand over the Saudi-born militant they will face the full wrath of the U.S. military.

"We told them (the Pakistani delegation) to give us proof that he did it, because without that how can we give him up?" Jamal said.

Asked if the Taliban had any other conditions for handing over bin Laden, Jamal said they wanted guarantees that, if charged, the multi-millionaire would face trial in a third country.

"We want proof first and we have been saying this for two years," he said, referring to demands for bin Laden's handover after the 1998 bombings of U.S. embassies in Kenya and Tanzania.

"If they had listened to us then, things would not have come to such a pass," he said.

SUFFERING, SYMPATHY

"Afghans have seen the same sort of suffering for a long time, they can sympathize with the Americans," the Information Minister said referring to the past two decades of war. "We appeal to the U.S. not to take any hasty decisions.

The Pakistani team met Mullah Mohammad Omar, the Taliban's reclusive spiritual leader, Monday in his southern stronghold of Kandahar to convey the gravity of the situation facing the Taliban if they continue to shelter bin Laden as a "guest."

They then flew to Kabul and had talks Tuesday with Mullah Mohammad Hassan Akhond, deputy head of the Taliban Council of Ministers and Foreign Minister Wakil Ahmad Muttawakil.

"Our response to them was that we should not hesitate in using sensitivity in the matter," the Foreign Minister told Reuters in Kabul. "Innocent people should not be killed"

Pakistani Foreign Ministry spokesman Riaz Khan refused to disclose the outcome of the trip. The team, led by intelligence chief General Mahmood Ahmed, had no plans to go back.

"The Pakistan delegation had fruitful talks here in Kabul by the grace of God," Taliban Information Ministry spokesman Abdul Rahman said.

Pakistan is one of only three countries to recognize the Taliban government and was a key backer of the purist Islamic movement when it seized most of the country in the mid-1990s.

But their ties may be fraying as Pakistan's military ruler, President Pervez Musharraf, has promised full cooperation with the United States.

WHAT WILL THE CLERICS SAY?

A decision on bin Laden will depend partly on results of a meeting of some 1,000 of Afghanistan's highest-ranking Islamic clerics now converging on Kabul in response to a call from Mullah Omar for a council, or shura, Wednesday.

The council, postponed for at least one day, would not only discuss what to do with bin Laden and whether to set conditions for his surrender but would also consider a call by Mullah Omar for a holy war in case of a U.S. attack and his recommendations after meeting the Pakistanis, Taliban officials said.

"Whatever message was given by them (the Pakistani team) to Aminul Momineen (Leader of the Faithful) will be presented before the ulema tomorrow for consideration," the Information Minister said.

It was unclear if the clerics had the authority to decide to surrender bin Laden given the reverence that surrounds his chief protector, Mullah Omar, who was not expected to attend, .

President Bush said Americans want bin Laden "dead or alive," and has said it would retaliate against anyone protecting the perpetrators of last week's attacks.

Mullah Omar has already warned that the Taliban would declare a jihad, or holy war, against the United States if it attacked and also against any country that helped Washington.

"I would like to tell my people that our jihad will be formally resuming against the Americans," Akhond, deputy chairman of the Taliban Council of Ministers, said on the Taliban's Voice of Shariat radio late Monday.

A Taliban spokesman told the Pakistan-based Afghan Islamic Press that Akhond had not announced a jihad but had only said the call would become compulsory if the United States attacked.