Guatemala’s President Bernardo Arévalo announced a 30-day state of siege on Sunday following the killing of seven police officers in the capital by suspected gang members.

Authorities said the violence appeared to be retaliation after security forces regained control of one of three maximum-security prisons in the southwest, where inmates had rioted and taken hostages the previous day.

The assaults on police in and around Guatemala City came after hundreds of anti-riot officers stormed Renovación prison in Escuintla, approximately 76 kilometers southwest of the capital, to rescue nine guards taken hostage.

Officials noted that gang leaders incarcerated within the prison often direct associates outside to carry out retaliatory attacks.

“They instigated riots within the prisons and seized hostages to compel the state to concede to their demands, which have been met for decades,” Arévalo said during a national television broadcast. He added that the subsequent attacks were “an effort to intimidate security forces and the public, aiming to pressure the government to ease its vigorous campaign against the gangs.”