Airlines revealed Russia has blocked some European flights avoiding Belarus airspace in a standoff over the arrest of a Belarusian journalist, as his parents pleaded Thursday for international help to get him released.

The G7 global powers also demanded Minsk release Roman Protasevich and the EU’s foreign policy chief threatened hard-hitting economic sanctions.

Belarus’s strongman President Alexander Lukashenko sparked international outrage by dispatching a fighter jet Sunday to intercept a Ryanair flight from Athens to Vilnius carrying Roman Protasevich, 26, and his girlfriend Sofia Sapega, 23.

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A nervous-looking Protasevich was last seen in a video released by Belarusian authorities on Monday in which he was seen supposedly admitting to helping to organise mass unrest, a charge that could land him in jail for 15 years.

“I want you to relay our appeal everywhere, throughout the world, to government representatives, to EU countries, to EU leaders, to US leaders: I am appealing, I am begging, help me free my son,” his mother Natalia told journalists in Warsaw, visibly moved.

Roman’s father, Dmitry said his son was “a tough man” and “a hero”.

“Throughout his life he fought for the truth and passed it on to people, which is why Lukashenko committed this despicable act,” he said.

The family and their lawyer confirmed that they have not had any communication with their son since his arrest.

At a briefing in Vilnius, where she fled to after last year’s election, exiled Belarusian opposition leader Svetlana Tikhanovskaya on Thursday called for an “economic boycott of the regime”.

Christophe Deloire, the head of media rights watchdog Reporters Sans Frontieres (Reporters Without Borders) was also in Lithuania to file a legal complaint against Lukashenko with prosecutors investigating Sunday’s incident.

Later on Thursday he protested on the Belarusian border along with dozens of Belarusian and Lithuanian journalists.

The International Civil Aviation Organization (ICAO) Council will meet as the consequences of the incident play out in Europe’s airspace.

EU countries are banning Belarusian carriers and the EU has also urged airlines to avoid Belarusian airspace.

On Thursday, Austrian Airlines said it had cancelled a Vienna-Moscow flight after Russian authorities did not approve a route change for it to avoid Belarusian airspace.

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An Air France flight from Paris to Moscow on Wednesday had to be cancelled for the same reason.

A defiant Lukashenko said he had “acted lawfully to protect our people” from an alleged bomb threat on the plane, in an address to parliament on Wednesday.

The criticism was nothing more than another attempt by his opponents to undermine his rule, he added.

Lukashenko — often dubbed “Europe’s last dictator” — is facing some of the strongest international pressure of his nearly 27 years ruling ex-Soviet Belarus.

He and his allies are already under a series of Western sanctions over a brutal crackdown on mass protests that followed his disputed re-election to a sixth term last August.

But he continues to enjoy solid support from Russian President Vladimir Putin, who is hosting the Belarusian leader on Friday.