MOSCOW — European airlines began skirting Belarus on Tuesday at the urging of the European Union, which also imposed new sanctions to punish the ex-Soviet nation's forced diversion of a passenger jet to arrest an opposition journalist.

In unusually swift action at a summit in Brussels, EU leaders agreed Monday to ban Belarusian airlines from using the airspace and airports of the 27-nation bloc, imposed sanctions on officials linked to Sunday's flight diversion, and urged the International Civil Aviation Organization to start an investigation into the episode some described as state terrorism or piracy. 

On Sunday, Belarusian flight controllers told the crew of a Ryanair jetliner flying from Greece to Lithuania that there was a bomb threat against the plane as it was crossing through Belarus airspace and ordered it to land. A Belarusian MiG-29 fighter jet was scrambled to escort the plane in a brazen show of force by President Alexander Lukashenko, who has ruled the country with an iron fist for over a quarter-century.

Belarus authorities then arrested 26-year-old journalist and activist Raman Pratasevich and his Russian girlfriend, Sofia Sapega. Pratasevich was later seen in a brief video clip shown on Belarusian state television, speaking quickly and saying that he was giving testimony about organizing mass disturbances.

Pratasevich, who left Belarus in 2019 and ran a popular messaging app that played a key role in helping organize huge protests against Lukashenko, has been charged in absentia with staging mass riots and fanning social hatred. Those charges carry a prison sentence of up to 15 years. 

The Telegram messaging app's Nexta channel that he co-founded has been labeled as "extremist" by the Belarusian authorities, and some fear Pratasevich could face more serious charges, including some that carry the death penalty.

U.S. President Joe Biden said late Monday that he asked his team to develop appropriate options to hold accountable those responsible, in close coordination with the European Union, other allies and partners, and international organizations.

"This outrageous incident and the video Mr. Pratasevich appears to have made under duress are shameful assaults on both political dissent and the freedom of the press," Biden's statement said. 

Belarus has been rocked by months of protests, which were triggered by Lukashenko's reelection to a sixth term in an August 2020 vote that the opposition rejected as rigged. More than 34,000 people have been arrested in Belarus since then, and thousands beaten.