Russian investigators have concluded that the plane that crashed on Sunday outside of Moscow exploded after hitting ground, said Investigative Committee Spokeswoman Svetlana Petrenko on Monday.

Russian investigators are still trying to to find the cause of the plane crash that killed all 71 people.

Emergency vehicles arrived late into the night at the scene where the passenger jet came down just outside Moscow.

Wintry conditions are hindering the investigation. Wreckage was strewn across a large area.

All possible causes for the crash, which was seemingly caught on a distant CCTV camera, are being considered. Officials have said one of the plane's flight recorders has been recovered.

"The content the flight recorders will enable experts of the IAC [Interstate Aviation Committee] to reconstruct the flight in detail and determine the cause of the crash," said Petrenko.

Among the possible causes investigators said they are looking into include weather conditions, human error and technical failure, but they have not mentioned terrorism. No distress signals were received from the crew.

Investigators are also looking over at documentation on the plane's maintenance and technical examination, and the crew's medical checkup at the office of Saratov Airlines, Petrenko added.

On Sunday (February 11), an Antonov An-148 commercial plane en route to Orsk from Moscow crashed in the Ramensky district in the capital's region.