Dozens of political prisoners who were released by Belarus as part of a US-brokered deal this week were forcibly deported, Sviatlana Tsikhanouskaya, a leader of the Belarusian opposition, said Friday.

Minsk freed 52 prisoners on Thursday as part of an agreement that was brokered by the United States, which will see sanctions on Belarus' national airline lifted.

The prisoner release was announced after White House special envoy John Coale met with Belarus' longtime authoritarian leader Alexander Lukashenko in Minsk.

The prisoners, who included a European Union employee, have been sent to Lithuania.

What did the Belarusian opposition say about the prisoner release?

The agreement could be a sign of improving ties between the US and Belarus, which has been ruled for over 30 years by Lukashenko and has faced yearslong sanctions and isolation from the West due to its close relationship with Moscow and its support for Russia's war in Ukraine.

"Of course, we are so happy to see people free, but let's be honest, what happened yesterday wasn't real freedom. It was forced deportation," Tsikhanouskaya told a press conference on Friday.

Some of the prisoners have thanked US President Donald Trump for his role in brokering the deal.

"I want to express my thanks," one former prisoner, Dzmitry Kuchuk, said. "If I hadn't been pardoned, I would have remained in jail for six more years."

But others have said they would have preferred to remain in Belarus, particularly since many of them were about to be freed anyway.

Tsikhanouskaya's senior adviser, Franak Viachorka, said around half of the prisoners who have been exiled to Lithuania were nearing the end of their terms.

"People were counting the days and months until their release, and suddenly they are deported, separated from their families; they have no passports, and they cannot return," he said.

Tsikhanouskaya, who also lives in exile in Lithuania, called on Western governments to demand that Lukashenko permit political prisoners to remain in their home country.

"People have to have the right to stay in Belarus," she said.

Prisoner releases are part of US-led efforts to end war in Ukraine

The prisoners who were freed this week are the largest group to be pardoned by Lukashenko.

But the number is far short of the 1,300 or 1,400 released prisoners Trump had called for.

In June, Tsikhanouskaya's husband, activist Siarhei Tsikhanouski was released along with 13 other prisoners after US mediation.

His release came after a rare high-level visit to the country by US special envoy for Ukraine General Keith Kellogg.

Kellogg was in Minsk for talks with Lukashenko, a close ally of Russian President Vladimir Putin, in an effort to facilitate an end to the war in Ukraine.

Edited by: Sean Sinico