Three days of mourning have been declared after a Soviet-era passenger plane crashed in Russia’s far-eastern Amur region, killing almost 50 people including children.

The plane, an Antonov An-24, was flying on a regional route from Khabarovsk to Blagoveshchensk and Tynda when it disappeared from the radar around 1pm local time (2pm AEST) on Thursday, the Russian Ministry of Emergency Situations said in a statement posted on Telegram.

The Amur Center for Civil Defence and Fire Safety said on Telegram that a search and rescue helicopter spotted the wreck of the aircraft on a mountain slope 16km from Tynda.

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It said no survivors were seen from the air.

It said that according to the director of Tynda airport, the plane caught fire after it crashed.

The emergency ministry said it is investigating why it lost contact, and the Interstate Aviation Committee has launched a probe.

The Russian government also set up a special commission tasked with dealing with the crash, which includes federal and regional officials.

The Kremlin said Russian President Vladimir Putin had been informed about the incident.

The Far Eastern Transport Prosecutor’s Office said in a statement on its website that the plane was attempting to land for the second time when it crashed, after failing to touch down on its first approach.

Russian state news agency TASS reported that the crew did not issue any distress calls, according to the emergency services, and that the weather at the airport was suitable for flying.

According to publicly available databases, the aircraft was built in 1976, and the Antonov AN-24 model was designed in 1957.

Vasiliy Orlov, the governor of Amur region, said on Telegram that according to preliminary data, there were 43 passengers, including five children, and six crew members on board the plane.

Citing emergency officials, Russian state news agency TASS said preliminary information indicates that all those aboard the aircraft were dead.

The aircraft was only a few miles from the Tynda Airport when it lost contact with air traffic controllers, the emergency ministry added.

Orlov said search and rescue operations were under way, with “all necessary forces and means involved” in the effort.

TASS reported the area where the plane went missing is remote and difficult to reach, with no roads through the swampy forest.

The Amur region has declared three days of mourning, and a hotline for families of those aboard and anyone else impacted by the crash has been set up.

The flight was operated by Angara Airlines, a Russian airline that is based in Irkutsk in Siberia.