A woman waits in Vilnius airport with a sign for the arrested journalist. (Photo: AFP)

Following the diversion of Ryanair flight FR4978 to Minsk by Belarus authorities and the arrest of journalist Roman Protasevich, world leaders have spoken out against President Alexander Lukashenko's government.

European Commission President Ursula Von Der Leyen called the actions "outrageous" and "illegal" before demanding Protasevich's release, and for sanctions to be used against those responsible.

Ireland's Foreign Minister Simon Coveney added the grounding of the plane was "utterly unacceptable" and warned in tweet: "Strong and united response from EU needed. EU inaction or indecision will be taken as weakness by Belarus."

UK Foreign Minister Dominic Raab called for Lukashenko to "be held to account" for the act.

@vonderleyen (Photo: Twitter)

@simoncoveney (Photo: Twitter)

But perhaps the most outspoken reaction has been that of Ryanair CEO Michael O'Leary. Talking to Irish radio station Newstalk O'Leary said the action amounted to "state-sponsored hijacking … [and] piracy."

The Irish businessman further accused "KGB agents" [sic] of traveling on the Ryanair flight and influenced the decision to reroute it to Minsk.

However, Russia's foreign ministry spokesperson Maria Zakharova said the reaction from "the West" was "shocking." Belarus's foreign ministry spokesperson also stated "Unfounded accusations are being made."

Flight FR4978's path, including altitude in color. (Photo: Flightradar24.com)

This map from Flightradar24.com shows the path of FR4978 that was on route to Vilnius, Lithuania.

Timeline of events

7.30 a.m. GMT Boeing 737 flight FR4978 took off from Athens, Greece;

9.46 a.m. Flight FR4978 makes an unscheduled turn east, away from Vilnius;

9.48 a.m. Flight FR4978 begins descent into Minsk;

10.16 a.m. The Boeing 737 lands at Minsk, where the passengers are forced to disembark and a bomb search begins;

5.47 p.m. Flight FR4978 takes off from Minsk without journalist Roman Protasevich;

6.26 p.m. Flight FR4978 lands in Vilnius.

Belarus's Foreign Ministry insisted the authorities acted "in full conformity with international rules" and believes the European response is merely politicizing the incident.

In a post on the ministry's facebook account, spokesperson Anatoily Glaz said the state would "guarantee complete transparency" before responding to questions about the international response. "We are struck by the haste with which some countries and European structures have made openly belligerent statements," Glaz said.

Who is Roman Protasevich?

Protasevich, 26, co-founded Poland-based online news service NEXTA, a popular opposition outlet in Belarus. Last year, the outlet was declared "extremist" after it was used to help organize major protests against Lukashenko.

According to the New York Times, the Belarus native has been living in Lithuania for the past few years in exile, fearing a prison sentence of up to 15 years in his home country.