Firefighters stand in debris of the plane near rail tracks. (Press Service of Russian Emergencies Ministry/AP) Engine failure likely caused the crash of an Aeroflot Boeing 737-500 jet in central Russia, which killed all 88 people on board, an investigator said Sunday.

Early inspections show the crash of Flight 821 was connected to technical defects of the aircraft's right engine, investigator Vladimir Markin said in televised remarks.

The plane caught fire and went down during an attempt to land in the Ural Mountains city of Perm, following a flight from Moscow early Sunday.

Witnesses compared the sight of the stricken aircraft to a burning comet, and the effect when it crashed to fireworks lighting up the sky. The wreckage burned on the ground for two hours before firefighters extinguished the blaze, witnesses said.

Aeroflot said the plane was flying at 3,600 feet (1,100 metres) when it lost contact with air traffic control and crashed, around 3:15 a.m. local time. The company said the plane was circling in low cloud cover.

Sections of the fuselage landed on a section of the Trans-Siberian rail line, forcing trains to divert around the Perm area, 1,200 kilometres southeast of Moscow.

An explosion at the crash site is seen on the outskirts of the city of Perm in central Russia. (Mikhail Mitin/Associated Press)

People living in houses just a few hundred metres away from the point of impact were awoken by the sound of the crash.

"I felt an explosion, it threw me off the bed. My daughter ran in from the next room crying 'What happened? Has a war begun or what?"' a woman in Perm who was not identified told Vesti-24 TV.

"My neighbours, other witnesses told me that it was burning in the air, it looked like a comet. It hit the ground opposite the next house, trailing like fireworks in the sky."

Investigators found the plane's "black box" flight recorders and were working to analyze them.

Among those killed were citizens from the United States, France, Turkey, Switzerland, Germany, Italy and Latvia, an Aeroflot spokesperson said.

Russian news agencies said one of the dead was Gen. Gennady Troshev, who in 2000 commanded the Russian army against separatist rebels in the north Caucasus region of Chechnya.

Emergency Situations Ministry spokeswoman Irina Andrianova said there was no indication of terrorism in the crash.

"We have no information that the aircraft exploded in mid-air," Interfax news agency quoted Russia's transport minister Igor Levitin as saying.

With files from the Associated Press