By Sudipto Ganguly and Shivam Patel

AHMEDABAD/NEW DELHI (Reuters) -India's aviation regulator has ordered all Boeing 787s being operated by local carriers to be inspected after an Air India crash killed 270 people this week, the aviation minister said on Saturday, adding the authorities were investigating all possible causes.

The aviation regulator on Friday ordered Air India to conduct additional maintenance checks on its Boeing 787-8/9 aircraft equipped with GEnx engines, including assessments of certain take-off parameters, electronic engine control tests and engine fuel-related checks.

"We have also given the order to do the extended surveillance of the 787 planes. There are 34 in our Indian fleet," aviation minister Ram Mohan Naidu told a media briefing in New Delhi.

"Eight have already been inspected and with immediate urgency, all of them are going to be done."

He did not say whether government officials will be involved in the inspections.

The Boeing 787-8 Dreamliner with 242 people on board bound for Britain's Gatwick Airport began losing height seconds after take-off on Thursday and erupted in a fireball as it hit buildings below, in what has been the world's worst aviation disaster in a decade.

Air India operates 33 Boeing 787s, while rival airline IndiGo has one, according to data from Flightradar24.

IndiGo did not respond to a request for comment.

In a statement, Air India said it is currently completing the one-time safety checks directed by the Indian regulator, adding that "some of these checks could lead to higher turnaround time and potential delays on certain long-haul routes."

The planes, however, have not been grounded, but a source on Friday told Reuters the Indian government was considering that as an option.

Naidu also said the government will look at all possible theories of what led to the crash.

Air India and the Indian government were looking at several aspects of the crash including issues linked to its engine thrust, flaps, and why the landing gear remained open as the plane took off and then came down, Reuters has reported.

At least 270 bodies have been recovered from the site of the crash, Dhaval Gameti, president of the Junior Doctors Association at B.J. Medical College, told reporters.

Only one of the 242 passengers and crew on board survived while others were killed as the plane struck the medical college's hostel as it came down.

The crisis has cast a shadow on Air India, which has for years struggled to rebuild its reputation and revamp its fleet after the Tata Group took over the airline from the Indian government in 2022. Tata's chairman said on Friday the group wants to understand what happened, but "we don't know right now."

Naidu said a government panel was investigating the crash and will issue a report within three months. "We are going to improve every necessary thing that is going to come our way, to improve the safety," he said at the briefing, declining questions from journalists.

LONG WAIT FOR FAMILIES

Dozens of anxious family members have been waiting outside an Ahmedabad hospital to collect bodies of loved ones killed in the crash, as doctors were working overtime to gather dental samples from the deceased to run identification checks and DNA profiling.

Rafiq Abdul Hafiz Memon, who lost four relatives in the incident, said he was not getting any answers from authorities and was "very hassled".

"We have lost our children ... we are not understanding anything. Please help us get information about our children. Tell us when they are going to release their bodies," Memon said.

Another father was upset about not being able to get the body of his son, Harshad Patel, saying he was told by authorities it will take 72 hours for DNA profiling. "The authorities are trying to help but our patience is running out," he said.

Most bodies in the crash were badly charred and authorities are using dental samples to run identification checks.

Jaishankar Pillai, a forensic dentist, told reporters on Friday they had the dental records of 135 charred victims, which can then be matched through reference to victims' prior dental charts, radiographs or other records.

Even for doctors, things are getting difficult, as the plane struck a hostel building of the B.J. Medical College, where many of the dead are undergoing identification checks.

"Most of us are struggling with our emotions and are mentally disturbed because of the loss of friends and colleagues," said one doctor who did not wish to be named.

"The loss of so many colleagues and friends in this incident is difficult."

(Reporting by Sudipto Ganguly and Sumit Khanna in Ahmedabad; Writing by Aditya Kalra; Editing by Stephen Coates, Raju Gopalakrishnan and Louise Heavens)