MUMBAI, India (CNN) -- Mumbai's police chief said Tuesday that he never received a warning of an impending seaborne attack on his city.
"[The warning] that terrorists could arrive by sea was from an intelligence report of last year that only said terrorists could attack Gujarat or industries in the south," Hasan Gafoor said.
Mumbai is in Maharashtra state, which borders Gujarat state.
Indian security forces have told CNN that U.S. officials warned the Indian government in New Delhi on two occasions about a waterborne attack in Mumbai. And according to a U.S. counterterrorism official, New Delhi was warned about a potential maritime attack on Mumbai at least a month before last week's massacre, in which at least 179 people were killed.
The area entered a higher state of alert for a week, including tightened security measures at hotels, but those efforts were eventually reduced, Indian officials said.
Gafoor said security was recently boosted at the city's hotels, but it was a precautionary move after a September attack on a Marriott Hotel in Islamabad, Pakistan.
In his first news conference since the attack, Gafoor said the 10 gunmen came to Mumbai after hijacking a vessel in the Pakistani city of Karachi to "create a sensation and kill as many people as possible."
He also said the attackers were on a suicide mission when they staged the coordinated attacks on several targets.
The band of gunmen attacked 10 targets in Mumbai on Wednesday night, sparking three days of battles with police and Indian troops in the heart of the city, which is the hub of India's financial and entertainment industries. Most of the 179 deaths occurred at the city's top two hotels: the Oberoi and the Taj Mahal. Watch new video of gunfire erupting at a cafe »
There is a rising tide of anger among Indians about the perceived lax security in Mumbai before the attacks, particularly in light of the reports that the government in New Delhi had been warned.
Surveillance video taken at Mumbai's Victoria Terminus train station -- one of the first targets -- shows a couple of local police cowering behind pillars as the attackers approach. Indian police constables are not armed, under Indian law, and CNN's sister station in India, CNN-IBN, reported that police retreated at the train station to call for backup.
Nine of the 10 attackers were killed by Indian forces, and Gafoor said none of the gunmen had any intention of surviving the onslaught. The only suspected attacker who survived was photographed at the train station holding what appeared to be an assault rifle.
That suspect is in police custody and "cooperating very well," Gafoor said. He has told police he is a Pakistani national. Indian intelligence sources have told CNN-IBN that police believe all the attackers were Pakistanis.
Gafoor said the attackers had "very detailed maps" of the city and used several taxicabs to get around Mumbai.
The attackers planted bombs in two of the taxis, resulting in explosions at two sites -- including Santa Cruz Domestic Airport -- in an attempt to divert attention from their main targets, the Taj Mahal and Oberoi hotels.
Ratan Tata, the chairman of the company that owns the the Taj Mahal hotel, told CNN that his company had been warned about the possibility of a terrorist attack before the massacre, but he did not say when.
He said the terrorists most likely waited until the security measures were relaxed at the hotel before carrying out their "very well-planned" attack.
Tata said the extra security measures would not have stopped the attackers from entering the building because they went through a kitchen door that was not monitored by a metal detector.
Gafoor said all of the attackers were trained by former army officers, but he would not elaborate on where they prepared for the attack.
"Some of them trained for a year, some of them for more than a year," he said.
Gafoor said other suspects linked to the attack have been questioned by investigators, but none is in police custody.
According to the foreign minister, the 10 attackers hijacked a trawler in the Pakistani port city of Karachi -- about 575 miles (925 kilometers) north of Mumbai -- and came ashore at Mumbai in dinghies. Gafoor said a Global Positioning System, or GPS, found with the attackers showed they had come from Pakistan.
Intelligence officials told CNN-IBN that the captain of the trawler was found dead, lying face-down with his hands bound behind his back. Four crew members who had been on board were missing, they said.
Gafoor said Indian officials will provide evidence backing their conclusions "once the investigation is complete."
India's Foreign Ministry on Tuesday briefed diplomats representing the countries that lost nationals in the attack -- including the United States and Britain -- about the ongoing investigation and the details of the attack, the ministry said.
India is calling on Pakistan's government to hand over a group of wanted militant leaders suspected of plotting the Mumbai attacks.
Indian External Affairs Minister Pranab Mukherjee said his country made the request in a demarche, or protest note, to Pakistan's top diplomat in India, according to the Press Trust of India.
"We will await the response of Pakistan," the foreign minister said.
Pakistani Foreign Minister Shah Mahmood Qureshi on Tuesday proposed a joint investigation into the attacks and said, "This is not the time to point fingers."
"We are ready to help India," he said. "We need to make a common strategy to fight with a common enemy. We need to show we're serious." Watch Pakistan's PM say his country will defuse tensions »
Pakistani Prime Minister Yousuf Raza Gilani told CNN on Monday that his government will provide "full cooperation" with Indian authorities investigating the attacks. But he said Indian officials have yet to present Pakistan with evidence regarding the massacre. Watch Anderson Cooper talk with Fareed Zakaria about the attacks »
India summoned Pakistan's high commissioner, the top-ranking Pakistani diplomat in New Delhi, to Mukherjee's office Monday to inform him that last week's massacre in Mumbai "was carried out by elements from Pakistan." It has been demanding the extradition of some of those militant leaders since a 2001 attack on India's Parliament that brought the South Asian nuclear rivals to the brink of war.
"The government expects that strong action would be taken against those elements, whosoever they may be, responsible for this outrage," a statement from India's Foreign Ministry said. "It was conveyed to the Pakistan high commissioner that Pakistan's actions needed to match the sentiments expressed by its leadership that it wishes to have a qualitatively new relationship with India."
The list reportedly includes Hafiz Mohammed, the head of Lashkar-e-Tayyiba, a now-banned Islamic militant group also blamed for the 2001 Parliament attack. Indian authorities said the lone remaining suspect in last week's attack was trained by Lashkar-e-Tayyiba.
Topping India's most-wanted list is Dawood Ibrahim, who allegedly masterminded the 1993 Mumbai bombings that killed nearly 250 people. India is also asking Pakistan to hand over suspected terrorist Masood Azhar, who was released from an Indian prison in 1999 in exchange for hostages aboard a hijacked Indian airliner.
CNN's Ram Ramgopal, Harmeet Shah Singh and Nic Robertson contributed to this report.