Bishkek (Kyrgyzstan) (AFP) – A veteran opposition leader in Kyrgyzstan was arrested on corruption charges Sunday, sparking nationwide protests as political tensions mount ahead of presidential elections in November.

The State Committee for National Security (GKNB) said Omurbek Tekebayev, who leads the nominally socialist Ata-Meken party, was detained after landing at Bishkek’s airport from Istanbul.

The opposition leader, a bitter adversary of incumbent President Almazbek Atambayev, will be held for at least 48 hours in connection with an investigation into corruption at a key telecoms company, the statement said.

Tekebayev’s arrest sparked protests around the Central Asian country, as his supporters blasted the accusations against him as “a fabrication”.

Around a thousand people gathering near the GKNB headquarters in Bishkek on Sunday, according to an AFP journalist, chanting “Freedom for Tekebayev”.

“This action by the authorities has made people lose patience,” Ata-Meken deputy Kanybek Imanaliev told AFP during the protest, calling the party chief’s arrest the “beginning of repressions” in Kyrgyzstan.

According to Imanaliev, in the span of a week, criminal investigations have been opened “without any legal basis” against three party members.

More demonstrations of between 20 and 250 people took place in other towns, including in the south where Tekebayev is from.

“Thousands of supporters of the opposition from all Kyrgyz regions are on their way to Bishkek,” Imanaliev told AFP, warning of a “coup d’etat” if authorities refuse to release the opposition leader.

Fresh protests are planned in front of the GKNB headquarters on Monday, he said.

While ex-Soviet Kyrgyzstan is the most democratic country in a region dominated by long-ruling strongmen, it has also been the most politically volatile in recent times.

The Muslim-majority country experienced two revolutions that unseated presidents in 2005 and 2010 followed by ethnic violence that left over 400 dead.

Tekebayev, 58, has so far not declared his intention to run in the presidential vote set for November 19.

He recently called for Atambayev to be impeached and demanded authorities probe the president and his family members for evidence of corruption.

Tekebayev’s arrest comes after two of his party colleagues were questioned for hours in unrelated corruption cases earlier this month.

The Ata-Meken party strongly opposed a referendum on constitutional changes in December that was driven by Atambayev’s office.

Atambayev is constitutionally restricted to a single six-year term and says he has no intention of easing into the office of prime minister, a position whose powers were boosted by the recent constitutional changes.

Two former prime ministers have announced their candidacy in the presidential election which, unlike other votes in Central Asia, will be keenly contested.