Russian rescue workers have found at least 200 body parts strewn across a snowy field near Moscow, where a passenger flight crashed on Sunday soon after taking off from the Domodedovo Airport, CNN reported on Tuesday.

All 71 people on board died after the Antonov AN-148 craft crashed. A team of 600 rescue workers are combing the site of crash, the report said.

Russia’s Aviation Committee said that so far around 400 pieces of the plane have been recovered, AFP reported. Officials said both flight recorders were recovered, but are yet to disclose details of their data or what could have caused the crash.

“The scatter of fragments of the aircraft and bodies of passengers occupies a large territory,” Svetlana Petrenko, a spokesperson for the Investigative Committee of Russia, told CNN. “The radius is not less than 1 km.”

The Russian Interstate Aviation Committee on Tuesday said the accident may have been a result of faulty information about the flight’s speed on the pilots’ indicators. “A factor in the development of a special situation in the flight could be the wrong data about flight speed on pilots’ indicators which was likely due to iced pitot tubes [speed probes] while their heating systems were shut off,” the committee said, according to AFP.

Investigating officials told AFP that the victims’ remains were so damaged that DNA testing will be required to confirm their identities.

Meanwhile, Ukraine’s state enterprise Antonov, which develops, produces and repairs the Antonov family planes, said it was ready to join investigations, Russian news agency TASS reported.