Protests in Kazakhstan that left at least 26 demonstrators and 18 law-enforcement officers dead gave way to an uneasy calm Saturday as some 2,500 Russian peacekeepers arrived in the country, The Washington Post reported.

During a week of unrest kicked off by an increase in the price of liquified petroleum gas, protestors burned the country’s presidential residence and stormed its largest airport. Around 4,000 people have been detained.

Kazakh authorities also announced Saturday that Karim Massimov, until recently a member of the country’s National Security Committee, had been detained on suspicion of high treason. The committee is Kazakhstan’s counterintelligence agency, the former Soviet republic’s successor to the KGB. Massimov served as prime minister from 2006–2007 and again from 2014–2016 during the tenure of President Nursultan Nazarbayev, the authoritarian leader who ruled Kazakhstan from its independence in 1991 until 2019.

Some observers suggest that, by arresting Massimov and calling in Russian troops, Kazakh President Kassym-Jomart Tokayev is attempting to escape the shadow of his predecessor, Nazarbayev, who handed the presidency to Tokayev but remained influential behind the scenes. Tokayev removed Nazarbayev from his powerful position as chair of Kazakhstan’s Security Council Wednesday.

Melinda Haring of the Atlantic Council’s Eurasia Center described events to NPR as “a coup by the current president, Tokayev, against Nazarbayev, the old president,”

Others warn that Russian President Vladimir Putin might seize the opportunity to further expand Russian power over former Soviet territory, a goal he appears to be pursing via his massive troop buildup on the Ukrainian border and his support for Bosnian Serb separatist Milorad Dodik.

“I think one lesson in recent history is that once Russians are in your house, it’s sometimes very difficult to get them to leave,” U.S. Secretary of State Anthony Blinken said Friday.