The United States Tuesday renewed its call on Pakistan to fully cooperate with the Indian-led investigation of the terrorist attacks in Mumbai. U.S. officials say they suspect a group based at least partly in Pakistan may be behind the operation. VOA's David Gollust reports from the State Department.

An Indian soldier takes cover as the Taj Mahal hotel burns during gun battle between Indian military and militants inside the hotel in Mumbai

The State Department is reiterating its call for full Pakistani cooperation with the investigation amid new indications that U.S. officials believe the Mumbai attacks may have originated in Pakistan.

A senior U.S. official traveling with Secretary of State Condoleezza Rice in Brussels told reporters there are a lot of reasons to believe the group behind the multi-pronged terrorist strike may be partially or entirely based on Pakistani territory.

The official, who said the assessment is based on a variety of information both public and private, spoke on the sidelines of a NATO foreign ministers meeting on the eve of a condolence visit by Rice to India.

State Department Deputy Spokesman Robert Wood told reporters it is too early for any definitive assessment of culpability.  

"Pakistan as the secretary has said over the last couple of days, needs to give its full, complete and transparent cooperation with the investigation into the Mumbai attacks, and to follow leads wherever they may go," he said. "And so, we're going to continue to work with India and Pakistan to see what we can do to prevent these kinds of attacks from taking place, and of course to get to the bottom of who carried out these attacks and bring those culprits to justice."

The official with the Rice party in Brussels commended India and Pakistan for their restraint in the crisis thus far, saying the United States has seen no military buildup along their border, or other overt signs that sharp rhetoric between the two powers will escalate to confrontation.

Spokesman Wood for his part, said the United States has given no green light for Indian military action against Pakistan despite repeated Indian charges the attacks were Pakistan-based.  He also noted the commitment of Pakistani President Asif Ali Zardari to follow the investigation wherever it leads.

U.S. intelligence officials have been quoted in recent days as suggesting that the Pakistani militant group Lashkar-e-Taiba may have been responsible for the Mumbai attacks.

The group, which has long been listed by the State Department as an international terrorist group, has carried out attacks from Pakistan into Indian-controlled Kashmir and is also blamed for a 2001 attack on India's parliament.

A senior official who spoke to reporters here said Lashkar-e-Taiba could very well have been behind the attacks but that it is too early to affix blame. He also said the sophisticated nature of the attacks - the apparent coordination and planning of them - has the hallmarks of al-Qaida.

The United States has sent an interagency team of experts, including agents of the Federal Bureau of Investigation, to Mumbai to support the Indian probe.