MOSCOW, Jan 8 (TASS) - A Russian-operated Boeing 737 airliner that declared an in-flight emergency during a domestic flight on Saturday landed safely at Moscow's Sheremetyevo airport, Tass news agency cited a civil aviation source as saying.

The plane, flying at an altitude of more than 10,000 metres (33,000 feet), sent the alert while en route from the Arctic port of Murmansk to Moscow, 1,500 km (930 miles) to the south.

The Tass report did not give any more details or identify the airline. S7, Russia's biggest private airline and the country's second largest carrier overall, offers flights between the two cities.