Belarusian officers arrested a prominent opponent of Belarus’ president on Sunday. They forced the airplane on which he was traveling to make an emergency landing after claiming a bomb threat. Opposition leaders and Western officials are calling the incident a government hijacking and an act of piracy. There was no actual bomb on board.

Raman Pratasevich is a Belarusian journalist and activist. He openly opposes the current Belarus President Alexander Lukashenko. Pratasevich lives in political asylum in Poland.

Pratasevich was aboard a Ryanair flight from Athens, Greece, to Vilnius, Lithuania. Suddenly, the plane changed course and headed for Minsk, the capital of Belarus.

“I saw this Belarusian guy with girlfriend sitting right behind us. He freaked out when the pilot said the plane is diverted to Minsk. He said there’s death penalty awaiting him there,” passenger Marius Rutkauskas said after the plane finally arrived in Vilnius.

“We sat for an hour after the landing. Then they started releasing passengers and took those two. We did not see them again,” Rutkauskas reports.

Flight trackers indicate the plane was about six miles from the Lithuanian border when it changed course.

Lukashenko’s press service claims the president learned of the bomb threat while the plane was over Belarusian territory. They say it was for that reason that he ordered a fighter jet to accompany the airliner. Deputy air force commander Andrei Gurtsevich says the plane’s crew made the decision to land in Minsk. However, Ryanair officials say that was not the case. The airline insists Belarusian air traffic control instructed the plane to divert to Minsk.

Lithuanian President Gitanas Nauseda calls the incident a “state-sponsored terror act” by the government of Belarus. He suggests banning Belarusian planes from all European Union airports and “serious sanctions” against Lukashenko’s government.

“Belarusian airspace is completely unsafe for any commercial flight, and it should be deemed this not only by the EU but by the international community,” says Lithuania’s foreign minister, Gabrielius Landsbergis.

Months of protests erupted in Belarus after last August’s presidential election. Official results gave Lukashenko a sixth term in office. Police cracked down on the protests harshly, detaining around 30,000 people and beating many of them. Officers also throttled protesters’ awareness of what was happening around the country by stifling access to news and social media.

Pratasevich is a co-founder of a channel called Nexta on a popular messaging app. The app gives Belarusians news about what is happening in the country—and criticizes the government. Pratasevich faces charges of inciting mass riots, provoking unrest, and violating public order in Belarus.

Belarus officials declared Pratasevich’s app “extremist” last year. Protesters used it to organize major protests against Lukashenko, including hideaway addresses, internet unblocking instructions, lawyer contact information, and maps of police locations.

From Poland, Pratasevich openly called the internet shutdown “a huge mistake by the authorities.”

Although protests died down during the winter, Belarus continues to take actions against the opposition and independent news media. Last week, police detained 11 staff members of a Belarusian news website.

Belarus officials found no explosives on board Pratasevich’s flight. But they escorted all passengers off the plane in Minsk. Five people did not reboard.

Belarusian authorities says there were 123 passengers on the plane. But Landsbergis, the Lithuanian foreign minister, says there were 171.

European Union leaders opened a two-day summit yesterday. The issue immediately shot to the top of the agenda. Meanwhile, the United States and other countries are demanding answers—and penalties—for the incident.

Lithuanian Defense Minister Arvydas Anusauskas says, “Lithuania has launched an investigation to find out what really happened on that plane.”

(Belarus police previously detained journalist Raman Pratasevich, center, in Minsk, Belarus, on Sunday, March 26, 2017. AP/Sergei Grits)