Kazakhstan’s former intelligence chief has been arrested on suspicion of treason, as the government seeks to restore order following violent protests that have left government buildings destroyed and dozens dead in the former Soviet country.

The January 6 detention of Karim Massimov was announced on Saturday by KNB, the National Security Committee that he had headed until Wednesday, when he was fired by the president, Kassym-Jomart Tokayev.

The move suggests that street protests, which began over rising fuel prices, triggered a power struggle between Tokayev and his predecessor Nursultan Nazarbayev, the country’s long-serving first post-Soviet president.

The protests had been largely peaceful but suddenly turned violent on Wednesday when armed men attacked security forces and stormed government buildings in the commercial capital Almaty. On Friday, Tokayev claimed 20,000 “bandits” had been involved in the assault.

Massimov, a former prime minister, was a close ally of Nazarbayev, who stepped down in 2019 but had retained control of the powerful Kazakh security council until Wednesday, when Tokayev ousted him and assumed the role himself.

Tokayev then imposed a state of emergency, instructing security forces to shoot and kill without warning, and asking Russia for help restoring order.

“It is clear Tokayev realised Massimov was a serious threat to his authority insofar as sections of the KNB would not take instructions from Tokayev but only Nazarbayev and Massimov. That clearly could not continue,” said Simon Glancy, founder of Kazakhstan-based Strategic Solutions risk and compliance consulting firm.

“Massimov is a very strategic and cautious operator. In my view, he has probably been set up and blackmailed as part of the current internal power struggle,” he said.

KNB, said it opened an investigation into acts of treason on January 6, and detained Massimov and other people “on suspicion of committing this crime”, according to Interfax.

Glancy said initial secrecy around Massimov’s arrest “only underlines we are very far from knowing the full picture”.

Tokayev, a protégé of Nazarbayev, had been regarded as an interim figure, while the former president retained control of the security apparatus and a role as “father of the nation”.

Massimov in effect controlled the country and was rumoured to have kept Tokayev under surveillance. That changed on Wednesday when Tokayev took control of the security council.

The KNB said Massimov’s deputy Samat Abish, who is Nazarbayev’s nephew, remained in his position.

Nazarbayev and his close relatives have not been seen in public since late-December and had been rumoured to have fled the country. On Saturday, his press secretary Aidos Ukibay said on that the former president was in Kazakhstan and in contact with Tokayev.