Grieving relatives of the passengers and crew killed in Tuesday's plane crash visited the crash site in Ukraine on Thursday as Russia marked a day of national mourning for the victims.

More than 100 family members of those on the Tupolev Tu-154 airliner, which plummeted into a Ukrainian field on Tuesday, arrived at the crash site near the city of Donetsk for a funeral service. There were no survivors on the plane, which was carrying 160 passengers and 10 crew members.

Flags were flown at half-mast and entertainment events were canceled in Russia. President Vladimir Putin ordered assistance to the relatives of the victims.

"Remembering the dead, we should be thinking about how we can help their relatives," Putin said at a meeting with King Juan Carlos I of Spain, the Itar-Tass news agency reported.

Ukraine marked a day of mourning on Wednesday.

Search for the victims was over and investigators have found the two flight data recorders of the jet, which belonged to Pulkovo Airlines and was flying from the Russian Black Sea resort of Anapa to St. Petersburg when it crashed in east Ukraine.

The cause of the crash was still unclear, but officials in Russia and Ukraine indicated that bad weather, other than terrorism, was likely to have contributed to the tragedy.

The weather conditions on the route of the Tu-154 were unusually hazardous, said Alexander Neradko, head of the Russian Federal Air Navigation Service.

"A highly critical meteorological situation was registered in the area of the Tu-154's flight. Such high thunderstorms happen very, very rarely," he said, quoted by the Interfax news agency.

Source: Xinhua