India's foreign ministry summoned Pakistan's high commissioner to New Delhi on Monday to officially inform him that "elements from Pakistan" were behind last week's attacks on Mumbai.
India also told Pakistan's government that it "expects that strong action would be taken against those elements," foreign ministry spokesperson Vishnu Prakash told The Associated Press.
Pakistan's president pledged Monday to work to improve relations with India but denied any government involvement in the attacks. The denial coincided with a U.S. demand calling for Pakistan to fully co-operate with the probe into the terrorist strikes.
Several Indian leaders have blamed the attacks on luxury hotels, a Jewish centre, public buildings, and a hospital on Pakistani-based terrorists.
Over the weekend, a top Indian police official said he believed the terrorists belonged to Lashkar-e-Taiba, a terrorist organization believed to be a rogue group created by Pakistan's intelligence service.
An unknown group calling itself Deccan Mujahideen has claimed responsibility for the attacks. But Indian officials said the lone surviving gunman who was taken into custody told authorities he belonged to a Pakistani militant group fighting over the disputed territory of Kashmir in the northern part of India bordering Pakistan.
Pakistani officials have denied any direct links between the terrorists and its government or agencies. Instead, the country's president suggested "non-state actors" were behind the attacks.
"Such a tragic incident must bring opportunity rather then the defeat of a nation," President Asif Ali Zardari said in an interview with Arj television, according to The Associated Press. "We don't think the world's great nations and countries can be held hostage by non-state actors."
Military analyst Sunil Ram told CTV's Canada AM that groups in Pakistan have historically launched attacks against India to thwart negotiations over disputed Kashmir.
"Ultimately, (Lashkar-e-Taiba) is a group that is used by Pakistan's security forces to fight India in an asymmetric war," he said.
Ram noted that the group, which was formed in 1989, is officially banned in Pakistan. He added, however, that there are elements within Pakistan that are upset that Islamabad may bow to U.S. pressure to remove troops from the Kasmir frontier and put them along its border with Afghanistan.
"This creates a serious problem for the Pakistan military because, of course, their raison d'etre since partition with India has been the fight against India to free Kashmir."
Ram noted, however, that any links between the Lashkar-e-Taiba and al Qaeda are "highly tenuous."
India officials said on Monday that they had fully cleared the Taj Mahal hotel of bodies and booby traps. But officials at the site, which was one of the main targets of the attacks, admitted that they remain apprehensive.
"We were apprehensive about more bodies being found. But this is not likely -- all rooms in the Taj have been opened and checked," Maharashtra state government spokesman Bhushan Gagrani told The Associated Press.
The 60-hour siege left nearly 200 hundred people dead, including two Canadians. The attacks unfolded on television as the world watched India security forces battle terrorists at locations throughout the city.
On Monday, the U.S. delivered a strongly worded message to Pakistan, telling officials there that they must investigate possible links between the terrorists and their country.
"I don't want to jump to any conclusions myself on this, but I do think that this is a time for complete, absolute, total transparency and cooperation and that's what we expect," Secretary of State Condoleezza Rice said.
"We share the grief and the anger of the Indian people but of course Americans were also killed in this attack and they were killed deliberately because they were Americans ... That makes this of special interest and concern to the United States."
Rice is expected to visit India later this week.
Meanwhile, Mumbai residents and Indians across the country are demanding answers about how a small band of gunmen could terrorize an entire city for almost three days. On Sunday, hundreds marched in Mumbai calling on New Delhi to fix the country's homeland security apparatus. On Monday, several top government officials resigned or offered to resign from their posts.
With files from The Associated Press
