An Aeroflot jet which crashed on Sunday near Perm in Russia's Ural mountains killing all 88 people on board was an accident, Russian Transport Minister Igor Levitin said.

Levitin told the Russian news agency Itar-Tass that explosive specialists working at the scene, believed the crash was an accident.

"(They) found no proof whatsoever confirming that it was an attack," Levitin said.

The black boxes had been recovered and their analysis — to establish the cause of the crash — would take three to four weeks, he added.

However Alexander Bastrykin, the Russian public prosecutor leading the investigation, said preliminary indications suggested the accident could have been caused by "technical failures."

He said the airplane crash had been linked to technical failures including a fire in the right-hand engine, he told Itar-Tass.

Aeroflot spokesperson Lev Koshlyakov had told journalists earlier on Sunday the plane had been given "a full technical inspection" early this year and was judged to be in a "proper condition."

Aeroflot said controllers lost radio contact with the plane around 5.20am (11.20pm GMT Saturday). Moments later it plunged to Earth, narrowly missing a densely-populated residential area on the outskirts of Perm.

It lost communication

"As the plane was coming in for landing, it lost communication at the height of 1100 metres and air controllers lost its blip," an Aeroflot statement said.

"The airplane was found within Perm's city limits completely destroyed and on fire," it added.

One witness described seeing the plane pass over his house before watching in horror as it exploded and sent massive chunks of burning wreckage flying to the ground.

"The plane was flying over our building, falling, and it hit the ground about 200 metres away and broke up," a local resident, who only gave his name as Maxim, told AFP.

"It blew up in the air, the pieces fell on the ground. The main part containing the passengers fell in a dacha (country house) area with gardens. It didn't hit the main residential area."

Clothes scattered wide

Vesti-24 showed smoking hot metal strewn across a wooded area and investigators combing through the dark with flashlights. Later pictures showed clothes and other possessions scattered far and wide.

The airline confirmed there were no survivors and said the dead included nine people from Azerbaijan, five from Ukraine and one each from France, Germany, Italy, Latvia, Switzerland, and Turkey.

One passenger was said to be American but US officials were checking that information. Six of the dead were crew.

Among the victims was General Gennady Troshev, a former top commander of Russia's war in Chechnya and advisor to ex-president Vladimir Putin, Interfax news agency reported, citing Russia's transport ministry.

The airline set up a crisis centre at Moscow's Sheremetyevo airport and in Perm for relatives of the victims and pledged compensation of up to two-million rubles (some $80 000 or €55 000) for each person lost.

It was the worst air disaster involving a Russian airliner since a Tupolev-154 flying to Saint Petersburg went down near the Ukrainian city of Donetsk in August 2006, killing all 170 passengers on board.

President Dmitry Medvedev offered his condolences to the grieving families and Russia's Transport Minister Igor Levitin was dispatched to Perm to personally head the probe into what happened.

Monday declared a day of mourning

Some of the grieving family members later flew out from Moscow to Perm, where Monday was declared a day of mourning.

Police said that the plane wreckage on the tracks had forced the closure of a stretch of the Trans-Siberian railway between Perm and Yekaterinburg.

The plane had been leased in July by Aeroflot from a Dublin-based company Pinewatch Limited until March 2013, the airline said. It was not clear how old it was.

The flight was operated by Aeroflot-Nord, a regional subsidiary of Russia's largest carrier.

The crash will doubtless raise renewed concerns about the safety of air travel in Russia where experts have pointed to major faults in the training of crews as well as Russia's ageing fleet of passenger jets.

An air safety commission announced in January that the average age of the country's international airliners was 18 years, and its regional jets 30 years.

AFP