A Russian passenger jet crashed in heavy fog and burst into flames on a highway in northwestern Russia late Monday, killing 44 people, officials said.

Eight people survived, dragged from the burning wreckage by locals.

The RusAir Tu-134 plane had taken off from Moscow and was moments from landing at the Petrozavodsk airport when it slammed into a nearby highway just before midnight, Emergencies Ministry spokeswoman Oksana Semyonova told The Associated Press.

Russia's top investigative agency said bad weather, human error or a technical malfunction might have contributed to the crash. There were no suspicions of a foul play.

The plane's approach was too low, so it clipped a tree and then hit a high-power line — causing the airport's runway lights to go off for 10 seconds — before slamming into the ground, Sergei Izvolsky, a spokesman for the Russian air transport agency, told the AP.

The ministry said in a statement on its website that 44 people were killed, including four with dual U.S. and Russian citizenship. Eight survivors, including a mother and her nine- and 14-year-old sons, were hospitalized in critical condition in Petrozavodsk.

The ministry said the crash happened just outside a small village, but no casualties were reported on the ground.

Tree struck on approach

The federal air transport agency chief, Alexander Neradko, speaking from the crash site, said that preliminary information indicated the plane appeared to be intact when hit a 15-metre pine tree. "There is no sign of a fire or explosion on board the plane before the impact," he said.

Sergei Shmatkov, an air traffic controller who oversaw the plane's approach, was quoted by the lifenews.ru online newspaper as saying the visibility near the airport was close to the minimum admissible level at the time of the crash, but the pilot still decided to land.

"The crew continued their descent at a moment when they already should have begun a second run," he was quoted as saying.

Shmatkov said he ordered the crew to abort the landing the moment the runway lights went off, but it already was too late.

A respected aviation expert and veteran pilot said pilot error appeared to be the likely cause.

"There is a strict rule — if you are on a glide path and you have not made a reliable eye contact with lights on the ground, there is no choice but to put engines at full throttle and make another run," said Oleg Smirnov, a former deputy civil aviation minister during Soviet times who now heads the nonprofit Partner of Civil Aviation Foundation.

Magomed Tolboyev, a highly decorated veteran Russian test pilot, said the Tu-134, while outdated, has a good reputation for its reliability and agreed that human error was the most likely cause.

"The human factor is always key, especially now when the level of crew training is very low and not controlled by the government," Tolboyev said, according to the Interfax news agency.

Flight data recorders recovered

The Tupolev 134, along with its larger sibling the Tu-154, has been the workhorse of Soviet and Russian civil aviation since the 1960s. The model that crashed was built in 1980, had a 68-person capacity and a range of about 2,000 kilometres.

The Karelia branch of the Emergencies Ministry said radio contact with the pilot was lost at 11:40 p.m. local time (3:40 p.m. ET). The black box flight data recorders have been recovered, the news agencies said.

Russian President Dmitry Medvedev and Prime Minister Vladimir Putin offered condolences to the victims' families, and the nation's transport minister flew to the crash site to oversee the investigation. Putin was attending the Paris Air Show on Tuesday to support dozens of Russian firms seeking sales contracts.

Russia and the other former Soviet republics have some of the world's worst air traffic safety records, according to the International Air Transport Association. Experts blame weak government controls, poor pilot training and a cost-cutting mentality for the poor safety record, leading to emergency landings being reported with alarming regularity.