At least nine commandos lowered themselves from an Indian air force helicopter onto the roof of Nariman House, which houses the Jewish centre, on Friday.
Security sources told Al Jazeera's Matt McClure that special forces have killed at least five attackers holed up inside the building, as efforts continue to take overall control of the block.
At least six hostages are being held inside the building, Mark Sofer, Israel's ambassador to India, has said.
Two workers and a child had escaped from the building a day earlier, the only people to emerge so far.
The child was identified as the son of Rabbi Gavriel Noach Holtzberg, the main representative at Chabad house.
The chief of India's national security guard said on Friday that his forces had taken control of another hotel, the Trident-Oberoi, killing two attackers who had taken hostages there.
"We are just now sanitising each and every room," JK Dutt said.
Some frightened civilians inside the hotel are refusing to leave their rooms, he said.
Twenty-four bodies were found inside the hotel, Hasan Ghafoor, Mumbai's police chief, said.
Although commandos have swept through most floors of the Taj Mahal hotel, a number of attackers are still thought to be inside.
Up to 200 people are believed to be still trapped in the hotels.
Sohail Rahman, Al Jazeera's correspondent in Mumbai, said the attackers holed up in the Taj appear to be mounting a strong resistance.
"Earlier it had been reported that security services had been able to take control of the Taj, but [as of about 0900 GMT] there was shooting from the second and third floors of the hotel, from gunmen holed up there," he said.
"Security services fired back but they have now restrained themselves because they believe there are a number of hostages still inside.
"That is quite a surprise considering that a few hours ago it was reported that they had control of the hotel and the Taj siege was over."
Meanwhile, the chief of India's Marine Commando Force said that his troops had come across "12 to 15 bodies" while sweeping through the Taj.
"The [attackers] were the kind of people with no remorse - anybody and whomsoever came in front of them, they fired," the commando said.
"We could have got those terrorists but for so many hotel guests ... The bodies were lying strewn here and there. There was blood all over and in trying to avoid the casualty of those civilians, we had to be that much more careful," he said.
Ratan Tata, who runs the company that owns the Taj Mahal hotel, said the attackers had detailed knowledge of the layout of the buildings.
The strikes by small bands of armed men starting on Wednesday night shocked Mumbai, the nerve-centre of India's growing economic might and home to the Bollywood film industry.
At least eight foreigners, including an Australian, a Briton, an Italian and a Japanese national, have been killed.
|Mumbai, a financial hub popular with tourists, is reeling after the attacks [AFP]
Seven attackers have been killed and nine suspects taken into custody, police have said.
Twelve policemen, including the head of Mumbai's counter-terrorism force, have also been killed, police say.
Indian government officials have been "very tight-lipped about the progress of the special forces at the locations where these attacks have happened", our correspondent reported.
"They are only giving out information as and when they can confirm it. They are making sure that they have a very tight lid on the information that is filtered out to the media," he said.
"So it is very difficult to asses exactly at what stage any of these forces or government officials are at in terms of planning in retaking buildings."
A US investigative team is heading to Mumbai, a state department official said on Thursday evening.
Meanwhile, the Indian media, 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 Hindu 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.
|India pressed anti-terror commandos into action after the attacks [AFP]
Earlier, a little known group calling itself the Deccan Mujahidin claimed responsibility for the attack in emails to news organisations.
Dipankar Banerjee, a retired Indian general, told Al Jazeera that he does not rule out the possibility that the Indian Mujahidin, blamed for previous attacks, were responsible for the Mumbai assaults.
In a speech on Thursday, Manmohan Singh, the Indian prime minister, blamed "external forces", a phrase sometimes used to refer to Pakistan-based fighters.
Pakistan has condemned the attacks and has said it will fully co-operate with an Indian investigation.
Al Jazeera's Kamal Hyder, reporting from Islamabad said: "More and more people here are inclined to think that this is an indigenous, internal Indian phenomenon and that India is scapegoating Pakistan.
"Since yesterday the Indian media insinuated that elements within Pakistan were involved. However on the Pakistani side there has been relative quiet and also a sense of responsibility shown by the journalists not to jump to conclusions," he said.