Earlier on Friday, the International Civil Aviation Organization (ICAO) Caouncil said during an urgent meeting that establishing the facts of the Ryanair airplane diversion in Belarus is of the utmost importance.

Rolandas Kiskis, the chief of Lithuania’s criminal police, said on Friday that the US Federal Bureau of Investigation (FBI) and Poland had launched their own investigations into what Western countries describe as the forced landing of a Ryanair plane in Belarus.

“In addition to Poland, which began its own pre-trial investigation, we have confirmed information from our colleagues in the U.S. that the Federal Bureau of Investigation has launched its own inquiry”, Kiskis told reporters.

The statement comes as the International Civil Aviation Organization (ICAO) Caouncil stressed the need to establish the facts pertaining to the Ryanair airplane diversion in the ex-Soviet republic.

“At a special meeting convened, the ICAO Governing Body underlined the importance of establishing the facts of what happened, and of understanding whether there had been any breach by any ICAO Member State of international aviation law, including the Convention on International Civil Aviation (Chicago Convention) and its Annexes,” the ICAO Council said in a statement following the meeting on Thursday.

On Sunday, a flight operated by the Irish airline Ryanair from Greece to Lithuania was diverted in the Belarussian capital Minsk over a bomb threat which later turned out to have been fake.

Western nations argued that the incident was a forced landing to arrest a passenger, dissident journalist Roman Protasevich, one of the founders of the opposition Telegram channel Nexta, which was active during last year’s post-election protests in Belarus and then designated as extremist.

Along with the journalist, a Russian national named Sofia Sapega was also detained. The Russian Embassy in Minsk maintains contact with her parents.