Commandos were combing through the Oberoi and the Taj Mahal, another luxury hotel and famous city landmark, for survivors and possible remaining attackers more than 24 hours after a string of well-organised strikes in the city left more than 120 people dead and over 300 injured.
Meanwhile, The Hindu, an Indian newspaper, citing unidentified police investigators, reported on Friday that three alleged attackers had confessed to being members of Lashkar-e-Tiyaba, a Pakistan-based group which aims to end Indian rule in Kashmir.
Lashkar-e-Tiyaba had earlier denied any role in the attacks.
The newspaper said interrogation of the suspects revealed that Lashkar operatives had left Karachi in Pakistan in a merchant ship early on Wednesday and went ashore at Mumbai on a small boat before splitting up into teams to attack multiple locations.
Manmohan Singh, India's prime minister, condemned the attacks on Thursday and blamed those "outside the country".
"It is evident that the group that carried these attacks, based outside the country, had come with single-minded determination to create havoc in the commercial capital of the country," he said.
"I strongly condemn these senseless acts of violence against innocent people, including guests from foreign countries.
"The well-planned and well-orchestrated attacks, probably with external linkages, were intended to create a sense of terror by choosing high-profile targets."
A little known group calling itself the Deccan Mujahedeen claimed responsibility for the attack in emails to news organisations.
But Mahan Abedin, an insurgency analyst, told Al Jazeera that "at this stage, that name does not necessarily mean that much".
"We have seen an increase in recent years in indigenous Indian Muslim organisations beginning to take a violent stance towards the Indian state and sections of the Indian society, particularly the commercial elite of places like Mumbai, in order to highlight, they would say, the sheer inequality of life in India.
"There is a middle class of around 100 million who live very well but 800 million-plus people live in miserable conditions," he said.
Gunfire and explosions were heard throughout Thursday from the Oberoi and Taj Mahal hotels where scores of terrified guests had been trapped in their rooms, and security forces said they were carrying out "mop up" operations to ensure all attackers had been subdued.
"They told everybody to stop and put their hands up and asked if there were any British or Americans … My friend said to me, 'don't be a hero, don't say you are British.'"
- Alex Chamberlain, British guest at the Oberoi Trident who fled via a fire escape
"That was, without doubt, the worst experience of my entire life … We could hear the army coming through the hotel ... The firemen broke the windows of the room and we climbed down the ladder."
- Female guest, Taj Mahal hotel
"They wore black T-shirts and blue jeans. They were carrying big guns … They just fired randomly at people and then ran away. In seconds, people fell to the ground."
- Nasim Inam, at Chhatrapati Shivaji railway terminus
"As I stepped inside the lobby gunshots started to go off ... There were people getting shot in the corridor. There was someone dead outside the bathroom."
- Brooke Satchwell, an Australian television actress, who hid in a cupboard in the Taj Mahal hotel
At the Taj Mahal three attackers were killed in gunfights with government troops and commandos, Indian officials said.
"We are fully in control of the situation. I am fully confident we will achieve our objectives," JK Dutt, the director of India's National Security Guards, said.
An estimated 100 armed men launched what India police called "terrorist attacks" on 10 locations in India's financial centre.
The attackers fired indiscriminately and threw grenades, hitting the historic Chhatrapati Shivaji train station, the Leopold Cafe popular with tourists and the police headquarters in southern Mumbai.
Several attackers were killed and at least nine others arrested, police said.
At least 11 policemen, including three senior officers, were killed in the attacks, among them Hemant Karkare, the chief of the city's anti-terrorism squad.
At least nine foreigners were also among the dead, police said, but most of those killed and injured were locals.
Witnesses at the hotels that were targeted said the attackers had singled out British and American citizens.
"They kept shouting: 'Who has US or UK passports?'" Ashok Patel, a British citizen who fled from the Taj Mahal hotel, said.
Several European legislators, visiting Mumbai ahead of a European Union-India summit, were among those inside the Taj when it was besieged.