A girl who was gravely wounded in a mass shooting in a school in Belgrade earlier this month has died, bringing the death toll to 10, authorities said Monday.

The girl died Monday morning at a children’s clinic in Belgrade, Serbia’s health ministry said, according to official media. The girl had been in critical condition with head injuries following the May 3 attack, said a statement.

The shooting happened in the Vladislav Ribnikar elementary school in central Belgrade when a 13-year-old boy took his father’s gun and opened fire, initially killing eight children and a school guard, and wounding six students and a teacher.

The first ever school shooting in Serbia stunned the Balkan country. A day later a 20-year-old randomly fired from an automatic weapon in two villages south of Belgrade, killing eight people and wounding 14.

The two mass killings in as many days triggered calls for action. Tens of thousands of people have marched in protests in Belgrade and other towns and cities demanding resignations of top officials and a ban on pro-government television stations that air violent content and host war criminals and crime figures.

Serbia’s populist government has launched a gun crackdown that includes a one-month amnesty for those who voluntarily hand over unregistered weapons, as well as stricter control of gun owners, a moratorium on new licenses and prison sentences for possession of illegal guns.

Police have said that citizens handed over some 13,500 various weapons by Sunday. The amnesty period will last until June 8, but analysts have warned that similar actions in the past have had limited success.

Critics of populist President Aleksandar Vucic say the increasingly authoritarian Serbian leader who is a former pro-Russian ultranationalist, has contributed to an atmosphere of intolerance in society by fostering hate speech against opponents and taking strict control over mainstream media and state institutions.

Vucic has denied this. He has suggested that he might call an early election for September in response to the protests and mounting public pressure over the shootings.