Belarusian President Alexander Lukashenko

The president of Belarus said Friday that his government thwarted a foreign-inspired plot to destabilize the ex-Soviet nation before the August presidential election in which he is seeking a sixth term.

The claim by President Alexander Lukashenko followed the detention Thursday of potentially his top election challenger, the former head of a Russia-owned bank, and reflects the growing strain in his relations with Russia.

The authoritarian Lukashenko, who has been in office for nearly 26 years, said, “The authorities have taken preemptive steps and derailed a comprehensive plan to destabilize Belarus.”

“We unmasked not only puppets here, but also some puppet masters outside Belarus,” he said.

Lukashenko didn’t name any specific country, but the statement follows his past rants about Moscow’s alleged plans to subdue its ally and neighbor.

Belarusian authorities detained potential presidential candidate and former Belgazprombank chief Viktor Babariko on Thursday after arresting 15 bank executives on tax evasion and money laundering charges and putting the bank under temporary administration.

The Kremlin said it wasn’t backing Babariko in the election but warned it would act to protect Russian business interests in Belarus.

Babariko, who has yet to formally register as a candidate, has denounced the arrests as part of an intimidation campaign. His supporters have 435,000 signatures, while a minimum of 100,000 is needed to qualify for the race.

Babariko is widely seen as the strongest of 10 candidates who plan to challenge Lukashenko, who has ruled the nation of 9.5 million with an iron fist since July 1994 and relentlessly cracks down on the political opposition and independent media.

Several thousand demonstrators formed a chain that spread for several kilometers (miles) across downtown Minsk on Thursday to protest Babariko’s detention.

Hundreds of protesters rallied again Friday, waving the historic white-red-white flags used by the opposition.

“The government opponents are behind bars and every protest is harshly suppressed,” said 20-year-old student Dmitry Romanov. “What kind of election is it?”

Police deployed in large numbers across the city center, blocking a central square where protesters gathered and closing subway entrances there. Police arrested several activists and journalists.

“Lukashenko has been scared by protests so much that he’s ready to accuse anyone, even Russia, of making plots and preparing revolutions,” said 45-year old dentist Igor Grishan.

Alla Rukhovich, a 35-year-old entrepreneur, said that “they have been telling us about plots for 26 years, but we mostly fear the president in office without end who led the country to economic ruin and isolation.”

The European Union called on the Belarusian authorities to free Babariko and “to ensure a meaningful and competitive political contest.”

“No potential candidate should be prevented from fulfilling the registration procedure due to politically motivated restrictive measures,” it said.

Belgazprombank is majority owned by Russia’s state-run Gazprom natural gas company and Gazprombank, which is affiliated with it. The Russian owners have criticized the Belarusian authorities’ decision on Monday to introduce temporary administration at the bank as a “flagrant violation” of Belarusian law and rules of a Russia-led economic alliance.

Ivan Tertel, the head of Belarus’ State Control Committee, charged Thursday that “big bosses at Gazprom and probably higher up” could have been involved in alleged violations at Belgazprombank.

Russian President Vladimir Putin’s spokesman, Dmitry Peskov, said Russia would protect Gazprom interests but denied allegations that the Kremlin was supporting Babariko’s presidential candidacy.

“The Kremlin doesn’t have any candidates in the Belarusian election,” Peskov said in a conference call with reporters.

Moscow long provided cheap energy to help keep Belarus’ Soviet-style economy afloat. Last year, the Russian government moved to cut the subsidies, arguing that closer economic integration between the two countries was needed for Belarus to continue receiving Russian oil and gas at low prices.

Lukashenko has rejected the Kremlin’s push for closer political and economic integration, casting it as part of Moscow’s efforts to force Belarus to abandon its post-Soviet independence. But even as he has regularly ranted against Russia’s policies, he has carefully avoided personal criticism of Putin.

“If some hope to set us against each other and worsen our relationship, they will not succeed,” Lukashenko told Russian Foreign Minister Sergey Lavrov, who visited Minsk Friday.

The Kremlin said Putin and Lukashenko also had a call Friday to discuss the coronavirus pandemic and the Belarusian president’s planned trip to Moscow next week to attend a Red Square parade marking the 75th anniversary of Nazi Germany’s defeat in World War II. Lukashenko’s office said the Belgazprombank situation wasn’t discussed during the call.

As the Aug. 9 presidential election approaches, Belarusian authorities have intensified efforts to disrupt the opposition, detaining about 100 opposition activists across the country. They included including popular blogger Sergei Tikhanovski, who was collecting signatures for his wife’s nomination as a presidential candidate. His wife said she was threatened along with their children.