Allies of Mikheil Saakashvili, the former Georgian president-turned opposition leader in Ukraine, say he was detained by masked men who they think acted on behalf of Ukrainian authorities.

Saakashvili's ally Liza Bogutskaya said on Facebook that Saakashvili was taken on Monday and is being driven to the airport in the capital, Kiev. She says Saakashvili's supporters would try to block the airport.

Other allies of Saakashvili say authorities may try to deport him to Poland.

Saakashvili moved to Ukraine in 2014 as an ally of President Petro Poroshenko ally, but was stripped of his citizenship last year. He was abroad when he lost his citizenship, but forced his way back into Ukraine in September. Since then, he has led repeated protests against Poroshenko, alleging the president is corrupt.