- Experts from Britain, France and Canada will help investigate
- The twin-engine plane crashes soon after takeoff, carrying 43 people
- The cause of the crash was not immediately known
- The crash is Russia's worst air disaster since a crash in Yaroslavl last year
A twin-engine plane carrying 43 people crashed soon after takeoff in Siberia on Monday, killing all but 12 people on board, Russia's Emergency Situations Ministry said.
The plane had taken off from the city of Tyumen and traffic control lost contact with it immediately afterward, the ministry said.
The ATR-72 plane was carrying 39 passengers and four crew members.
UTair, the flight operator, said the plane was trying to make an emergency landing when it went down, the RIA-Novosti news agency said.
Twelve survivors were taken to hospitals, while everyone else on board, including all four crew members, was killed, ministry said.
The survivors were in intensive care, RIA-Novosti said.
Authorities could not say with certainty what caused the crash. Officials have recovered the plane's data recorders, which will help shed light on what happened in the flight's final minutes.
"Malfunction and pilot's error are considered to be the most likely causes," Vladimir Markin, a spokesman for the Russian Investigation Committee, told the Itar-Tass news agency.
Russian President Dmitry Medvedev has postponed a meeting with the opposition light of the crash, his spokeswoman Natalya Timakova said.
Specialists from France, Canada and Great Britain will take part in the crash investigation, the Itar-Tass news agency reported, citing the Russian Interstate Aviation Committee.
The plane was built in France and was registered in Britain. The engine was produced in Canada, the agency said.
The crash was the the country's deadliest air disaster since a crash in Yaroslavl that killed 44 people in September.
Dozens of Yaroslavl Lokomotiv professional hockey players died in that crash, including several former National Hockey League players.
Only one person survived the crash, which investigators found was caused by pilot error, RIA-Novosti reported.