Moscow (CNN) -- Officials searched for answers Tuesday after a Russian jetliner made a premature descent and burst into flames in the country's northwest, killing 44 people and injuring eight others.

"I do not want to prejudge the investigation and all that but preliminary information suggests an obvious pilot error in poor weather conditions," said Russian Deputy Prime Minister Sergei Ivanov, the state-run RIA-Novosti news agency reported.

Investigators recovered the flight data recorder and cockpit voice recorder from the site of the crash, according to the Investigative Committee probing the crash.

The cause of the premature descent is being investigated by the Inter-State Aviation Committee and the so-called black boxes will be recovered and sent to Moscow for deciphering, said Russian Deputy Transport Minister Valery Okulov on Russian state TV.

The recorders will help authorities piece together the final minutes of the flight and possibly tell investigators what caused the plane to go down.

"Seems that he had been visually looking for the runway but couldn't see it," Ivanov said.

The dead included 36 Russians, four people with joint U.S.-Russian citizenship, a Swede, a Dutchman and two Ukrainians, according to the Transport Ministry.

Of the injured, five are in critical condition, according to regional authorities in Petrozavodsk. Some will be transported to Moscow for medical treatment.

President Dmitry Medvedev expressed his condolences in the aftermath and has sent Transport Minister Igor Levitin to the scene on a fact-finding mission.

The families of the dead will receive 1 million rubles ($35,500), while the families of the injured will be compensated 500,000 rubles ($17,750), according to the authorities.

The jet with 43 passengers and a crew of nine took off Monday night from Moscow for Petrozavodsk, about 950 kilometers (600 miles) to the north.

Controllers lost contact with the twin-engine Tupolev-134 about 11:40 p.m. (3:40 p.m. ET), and it crashed onto a highway outside Besovets, near the Petrozavodsk airport, the ministry reported.

"The first thing that the plane had contact with was a pine tree of about 15 meters high," said Alexander Neradko, head of the Russian Federal Aviation Agency on Russian state TV.

"This proves that the plane didn't break in mid-air but that all those destructions were inflicted to it as a result of that contact," he said.

Nearly 140 rescue workers, doctors and police officers were on the scene before dawn Tuesday.

Forensic experts have been dispatched to the crash site to help with identification of the bodies, regional authorities said.

CNN's Maxim Tkachenko contributed to this report.