The former head of Kazakhstan’s counter-intelligence and anti-terror agency has been arrested on charges of attempted government overthrow in the wake of violent protests that the president has blamed on foreign-backed terrorists.

The arrest of Karim Masimov was announced on Saturday by the National Security Committee, which Masimov headed until he was removed this week by President Kassym-Jomart Tokayev.

Authorities say security forces killed 26 demonstrators in this week’s unrest and that 18 law-enforcement officers died. More than 4,400 people have been arrested, the Interior Ministry said on Saturday.

The protests in the Central Asian nation were the most widespread since