MOSCOW, Russia (AFP) — The pilots of a plane that crashed and killed Poland’s president had received explicit weather warnings before they attempted to land at a fog-bound Russian airport, investigators said yesterday.

Russian officials said flight data showed air traffic controllers recommended the crew divert to another airport while Polish prosecutors said there was no indication they were pressured by those onboard to override the advice.

As crews battled to retrieve bodies from the wreckage of a crash that killed all 96 people on board, including much of Poland’s political and military elite, experts also struggled to identify mutilated remains.

Poland meanwhile announced that a memorial service would be held on Saturday for President Lech Kaczynski and the other victims of the country’s worst tragedy of the post-war era. They were heading to a memorial service for Poles massacred after their capture by Soviet forces in World War II.

Kaczynski’s body is the only one so far to have been repatriated to Poland where he will lie in state from Tuesday.

Grieving relatives have been flown to Moscow to try to speed up the process of identifying the corpses, many of them disfigured beyond recognition.

Police formed a tight security cordon around the city morgue, where buses brought the families to attend the identification.

“We all had to fulfill this difficult duty,” said Rafal Dobrzeniecki, whose fiancee’s father died in the crash. “I never had the chance to call him my dear father-in-law, he will always stay in my memory.”

Russian Health Minister Tatyana Golikova said 24 of the victims have been identified by their relatives, but her Polish counterpart Ewa Kopacz warned some of the bodies would only be identifiable by DNA tests.

The head of Poland’s prosecution said that some bodies remained trapped in the wreckage in a forest near the western Russian city of Smolensk.

“Work is ongoing to build an access route for heavy machinery which will be used to raise the major parts of the aircraft and remove the remaining bodies,” chief prosecutor Andrzej Seremet told reporters, adding that 87 bodies have been located.

Kaczynski’s plane clipped trees on its fourth approach as it tried to land in thick fog.

Russian Prime Minister Vladmir Putin, who has taken charge of the crash probe, promised an “objective and thorough” investigation.

“It goes without saying that we will do everything to ensure that the investigation is objective and thorough,” he told a cabinet meeting.

Deputy Prime Minister Sergei Ivanov said flight data confirmed the crew received a warning about bad weather at Smolensk airport.

“It has been positively confirmed that the warning about unfavorable weather conditions at Severny airport, and the recommendation to divert to a standby airport, were not only transmitted but were received by the crew,” he said.

Ivanov said the plane’s black box was in a “satisfactory” condition and both the voice recordings and the recordings of systems data were intact.