Pilots on the Air India plane that was stranded in Russia had received an indication of low oil pressure in one engine, forcing them to land at a nearby airport, the airline said on Thursday.

Air India's replacement flight to ferry passengers to the original destination of San Francisco landed on Thursday, with the airline mobilising additional support to carry out clearance formalities for passengers upon arrival, it said.

The original stranded aircraft's 216 passengers and 16 crew had been housed in makeshift accommodation at Russia's remote Magadan airport.

Facilities at Magadan "may not have met the standard" Air India normally aims to provide, the airline said in a letter apologising to passengers for the delay in reaching San Francisco.

Angry passengers had complained on Wednesday about inadequate food at their accommodation, which they said looked like a school.

The Boeing 777 plane was on its way from Delhi to San Francisco before being diverted on Tuesday.

(Reporting by Kanjyik Ghosh in Bengaluru and Tanvi Mehta in New Delhi; Editing by Himani Sarkar, Gerry Doyle and David Goodman)