MOSCOW — Investigators are examining flight recorders and other evidence to try to determine the cause of the airliner crash in Moscow that killed four people.

The Tu-204 belonging to Russian airline Red Wings was carrying eight people, all of them crew members, when it careered off the runway Saturday while landing at Moscow's Vnukovo Airport. It went partly into an adjacent highway, broke into pieces and caught fire.

The jet was being flown back from the Czech Republic without passengers to its home at Vnukovo. 

The four survivors were reported in critical or serious condition in Moscow hospitals.

Vladimir Markin, a spokesman for Russia's main investigative agency, was quoted by Russian news agencies Sunday as saying the data recorders were being examined, along with fuel samples.

In addition, he said flight documents for the plane have been taken from the airline for examination.

On Saturday, Russia's state television showed photos of the plane's wreckage, with the cockpit sheared off from the fuselage and a large chunk gashed out near the tail.

The crash occurred amid light snow, but other details were not known.

Vnukovo airport spokeswoman Yelena Krylova said Saturday it had enough personnel and equipment to keep the runway fully functional. The airport resumed receiving planes after a break of several hours.

Prior to Saturday's crash, there had been no fatal accidents reported for Tu-204s, which entered commercial service in 1995. The plane is a twin-engine midrange jet with a capacity of about 210 passengers.

Vnukovo, on the southern outskirts of Moscow, is one of the Russian capital's three international airports.