Foreign Ministry spokesman Vishnu Prakash has told reporters Pakistan's high commissioner to India was summoned and told that "elements from Pakistan" had carried out the attacks.
India "expects that strong action would be taken against those elements," he says the high commissioner was told.
The series of coordinated attacks on at least ten sites across India's financial capital left at least 172 people dead.
THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.
MUMBAI, India (AP) — Soldiers removed the remaining bodies from the shattered Taj Mahal hotel on Monday, searching each room in the labyrinthine building and defusing booby-traps and bombs left by the gunmen who killed 172 people during three days of terror.
The United States, meanwhile, called on Pakistan to fully cooperate with investigations into the siege, which India has blamed on a banned Pakistani militant group. Mumbai's most influential Muslim cemetery rejected the corpses of nine of the gunmen and said "Islam does not permit this sort of barbaric crime."
The 60-hour attack was apparently carried out by just 10 gunmen and exposed the weakness of India's security forces. The country's top law enforcement official resigned amid growing criticism that the attackers appeared better trained, better coordinated and better armed than police. Two provincial officials offered to step down on Monday.
An Indian police official said the only gunman captured alive after the attacks claimed to belong to Lashkar-e-Taiba, a Pakistani militant group with links to the disputed Himalayan region of Kashmir and one long seen as a creation of the Pakistani intelligence service.
Pakistan must "follow the evidence wherever it leads," Secretary of State Condoleezza Rice said London. "This is a time for complete, absolute, total transparency and cooperation and that's what we expect."
Pakistani President Asif Ali Zardari said the men who attacked India's financial and entertainment capital had no links to any government. He called the attackers "non-state actors," and warned against letting their actions lead to greater enmity in the region.
"Such a tragic incident must bring opportunity rather than the defeat of a nation," Zardari said in an interview with Arj television. "We don't think the world's great nations and countries can be held hostage by non-state actors."
In Mumbai, security forces declared the landmark 565-room Taj Mahal hotel — the scene of Saturday's final battle — cleared of booby traps and bodies.
The army had already cleared other sites, including the five-star Oberoi hotel and the Mumbai headquarters of an ultra-Orthodox Jewish group. Israeli emergency workers sorted through the shattered glass and splintered furniture at the Jewish center Monday to gather the victims' body parts. At one point, one of the men opened a prayer book amid the rubble and stopped to pray.
Joint Police Commissioner Rakesh Maria said the sole gunman known to have survived the attack, Ajmal Qasab, said he was trained at a camp in Pakistan.
The announcement blaming militant group Lashkar-e-Taiba threatened to escalate tensions between India and Pakistan. However, Indian officials have been cautious about accusing Pakistan's government of complicity.
Foreign Ministry spokesman Vishnu Prakash denied a news report that India was preparing to end a 2003 cease-fire with Pakistan. An intelligence official, speaking on customary condition of anonymity, said there was no unusual mobilization of troops along the India-Pakistan border.
The group the Indians have blamed, Lashkar, was banned in Pakistan in 2002 under pressure from the U.S., a year after Washington and Britain listed it a terrorist group. It is since believed to have emerged under another name, Jamaat-ud-Dawa, though that group has denied links to the Mumbai attack.
A Muslim graveyard in Mumbai on Monday rejected the bodies of the nine dead attackers.
"People who committed this heinous crime cannot be called Muslim," said Hanif Nalkhande, a trustee of the influential Jama Masjid Trust, which runs the 7.5-acre (three-hectare) Badakabrastan graveyard in downtown Mumbai. "Islam does not permit this sort of barbaric crime."
While some Muslim scholars disagreed with the decision — saying Islam requires a proper burial for every Muslim — the city's other Muslim graveyards are likely to do the same.
Mumbai returned to normal Monday to some degree, with parents dropping their children off at school and many shopkeepers opened their doors for the first time since the attacks began.
"I think this is the first Monday I am glad to be coming to work," said Donica Trivedi, 23, an employee of a public relations agency.
Indian officials said their country would not be broken.
"This is a threat to the very idea of India, the very soul of India," Palaniappan Chidambaram, the just-named home minister, the country's top law enforcment official, told reporters. "Ultimately the idea of India — that is a secular, plural, tolerant and open society — will triumph."
India's previous home minister resigned Sunday, as more details of the response to the attack emerged and a picture formed of woefully unprepared security forces.
"These guys could do it next week again in Mumbai and our responses would be exactly the same," said Ajai Sahni, head of the New Delhi-based Institute for Conflict Management and who has close ties to India's police and intelligence.
Prime Minister Manmohan Singh promised to strengthen maritime and air security and look into creating a new federal investigative agency.
Singh promised to expand the commando force and set up new bases for it around the country. He called a rare meeting of leaders from the country's main political parties, hours after the resignation of Home Minister Shivraj Patil.
Among the 19 foreigners killed were six Americans. The dead also included Germans, Canadians, Israelis and nationals from Britain, Italy, Mexico, Japan, China, Thailand, Australia, Singapore and Mexico.
Indian stocks fell sharply on the first day of trading after the end of the siege. The Bombay Stock Exchange Sensitive Index, or Sensex, closed down 252.85 points, or about 2.8 percent.
While the attacks could keep tourists and foreign investors away, some analysts attributed Monday's declines to shock and anxiety in the immediate aftermath rather than a loss of confidence in India's economic prospects.
Associated Press reporters Ravi Nessman, Paul Peachey, Anita Chang and Ramola Talwar Badam contributed to this report from Mumbai, Ashok Sharma contributed from New Delhi and Asif Shahzad from Islamabad, Pakistan.