The Beechcraft King Air C90B, on a charter flight from the Czech Republic, was lost to radar contact at around 5:00 p.m. Ukrainian time (3:00 p.m. GMT), and crashed into a field 300 meters from the airport killing the two pilots and three passengers on board, all Czech nationals.
The Ukrainian Prosecutor General's Office launched on Monday a criminal case on charges of violations of air transport safety regulations resulting in death.
However Oleksandr Lysnyak, first deputy chairman of the Ukrainian State Aviation Administration, said turbulent weather was now being considered as one of the most likely causes. The investigation is ongoing, he added.
"We will be able to give the final results of the investigation only after all examinations are concluded," said Lysnyak, who is also in charge of the committee investigating the incident.
He also said human error could have been the cause of the crash: "Before the incident occurred, we maintained contact with the pilot, but for some reason he failed to follow two of the four recommendations given by the air traffic controller."
The investigation committee is also considering technical problems as a possible cause, Lysnyak said.
The Czech CTK news agency earlier quoted witnesses as saying that the aircraft exploded in mid-air as it was preparing to land.
