Police prevented another pro-Russian opposition politician from leaving ex-Soviet Moldova on Thursday as the detention of the leader of the country’s pro-Russian Gagauz ethnic minority further strained relations with Moscow.

Eugenia Gutul, the leader, or bashkan, of Gagauzia, has been in detention since being stopped at the airport on Tuesday in connection with a corruption probe. On Thursday, she urged Russian President Vladimir Putin to help secure her release.

Russia has denounced her detention, saying Moldova is persecuting politicians opposed to pro-European President Maia Sandu.

Two pro-Russian parliamentarians, also charged with corruption, have disappeared in the past week.

All those under suspicion or facing charges are associates of fugitive pro-Russian business magnate Ilan Shor, sentenced to 15 years in prison in connection with the 2014-2015 disappearance of $1 billion from the Moldovan banking system.

Alexei Lungu, a member of the pro-Russian opposition, was stopped at Chisinau airport on Thursday and told he could not leave the country. He told Reuters the action amounted to “revenge and political terror.”

“We will fight – both openly and lawfully. Neither intimidation nor blackmail will stop us,” he said.

Gagauzia, a region of 140,000 people in the south of Moldova, is dominated by ethnic Turks who favour close ties with Russia, adhere to Orthodox Christianity and have had uneasy relations with central authorities since Moldovan independence in 1991.

In her appeal, Gagauz leader Gutul asked Putin “to use the entire arsenal of diplomatic, political and legal means to put pressure on Moldovan authorities to secure an immediate end to political repression and my rapid release.” She issued a similar appeal to Turkish President Tayyip Erdogan.

A Chisinau court postponed until Friday a decision on a prosecution request to extend her 72-hour detention.

Gutul is due to be sentenced soon on charges of corruption and financing a political bloc led by Shor from exile in Russia.

Sandu is spearheading a drive to secure European Union membership for Moldova, one of Europe’s poorest countries, and has never recognised Gutul’s 2023 election as bashkan.

The president has denounced Russia’s invasion of Ukraine, which is on Moldova’s eastern border, and has accused the Kremlin of trying to unseat her.

Gutul’s detention follows the unexplained disappearance last week of pro-Russian parliamentarian Alexandr Nesterovschi on the day he was sentenced to 12 years in prison on similar corruption charges. A second lawmaker, Irina Lozovan, awaiting a verdict on similar charges, has also disappeared.

Moldovan authorities accuse Shor of funnelling money into the country illegally with the aim of using his banned “Victory” bloc to secure the election of pro-Russian lawmakers in a parliamentary poll later this year.