A former opposition presidential candidate in Belarus has been arrested while returning to his country after four years in exile.

Ales Mikhalevich was among nine candidates who were arrested after the 2010 presidential election, which was won by the former Soviet republic's authoritarian leader. He was released after two months in a KGB jail and fled to the Czech Republic, where he received political asylum.

The border service said Mikhalevich was arrested Tuesday while crossing into Belarus from Lithuania.

Writing on Facebook, Mikhalevich said he decided to return after President Alexander Lukashenko last month pardoned all six political prisoners, including Nikolai Statkevich, the only former opposition presidential candidate still behind bars.

Freeing political prisoners was a condition set by the European Union and United States for improved relations with Belarus.