WASHINGTON — Evidence suggests that a group partly based in Pakistan carried out last week's attack in India, U.S. officials said today, also revealing that the U.S. had warned the Indian government beforehand that terrorists appeared to be plotting an assault on Mumbai.

The brutal, prolonged attack on India's financial capital has some roots in Pakistan, a senior State Department official said. That's the closest the U.S. has come to placing blame for the coordinated assaults, although the official was careful to say that not all the evidence is in. The official spoke on condition of anonymity because the investigation is ongoing.

Indian authorities have claimed a Pakistan connection for days, but the United States has not wanted to "jump to conclusions," as Secretary of State Condoleezza Rice said Monday. The administration fears that any misstep amid the extraordinarily high emotions surrounding the three-day assault, which killed 172 and wounded 239 in the heart of Mumbai, could spark new and possibly deadly tensions between longtime, nuclear-armed rivals India and Pakistan.

Rice is set to visit India on Wednesday, carrying the U.S. demand that Pakistan cooperate fully in the investigation into the attacks and try to cool cross-border tempers. Among those killed in Mumbai were six Americans, White House press secretary Dana Perino said.

According to a senior administration official, Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, has also been asked to go to the region. Mullen, who has visited Pakistan a number of times in the past year and worked to improve relations with officials there, left abruptly today.