Air India said a reserve plane would leave from Mumbai on Wednesday for passengers whose flight was diverted to Russia's Far East on Tuesday after the Boeing 777 widebody aircraft faced an issue with one of its engines.

216 passengers and 16 crew who were on board the flight from Delhi to San Francisco had been moved to makeshift accommodations, given infrastructure limitations around the airport, the airline said.

The diversion had raised questions over how quickly the $200 million Boeing 777 U.S.-built plane, whose engines are made by General Electric, could be repaired amid U.S. and European Union sanctions on exports of aviation items to Russia.

A source at the Magadan airport in Russia told Reuters that Air India engineers will arrive on the reserve plane along with the necessary spare parts.

A stranded passenger named Gagan told Indian broadcaster NDTV that there were many U.S. citizens on the flight and that given the tensions between Russia and the United States, "there are a lot a nervous people here".

Air India did not immediately respond to a request to share the nationalities of the passengers.

U.S. State Department deputy spokesman Vedant Patel said on Tuesday it is "likely" there are Americans onboard given its planned destination.

"We are aware of a U.S.-bound flight that had to make an emergency landing in Russia and are continuing to monitor that situation closely," Patel said.

Aggrieved passengers took to Twitter to complain about the inadequate supply of food at the building which they said looked like a school.

A user tweeted that his mother, who was travelling on the flight, was given tea, bread and some rice the previous day.

There was no contact for the past few hours in order to save charge on her phone as there was only one power outlet available in the premises.

Air India said it was coordinating with Indian and Russian authorities as the company did not have any staff in Russia.

It was not immediately clear if the reserve plane had taken off. It was scheduled to leave Mumbai at 0730 GMT and head to Magadan in Russia, carrying food and other essentials for those stranded. (Reporting by Tanvi Mehta in New Delhi, Lidia Kelly in Melbourne and Gleb Stolyarov, additional reporting by Krishna N. Das; Editing by Gerry Doyle, Elaine Hardcastle)