Serbian Education Minister Branko Ruzic resigned on Sunday, days after an attack on a Belgrade school left nine people dead, News.ro reported, citing Reuters.

Serbia is in a state of shock after two bloody attacks: a massacre at a school in Belgrade on Wednesday and an attack on Thursday evening in a rural area near the town of Mladenovac that killed eight people. The perpetrators of both attacks, a 13-year-old boy and a 20-year-old boy, are in custody.

Opposition parties, which accuse the government of failing to prevent the two tragedies, called on their supporters to take part in an anti-government march in Belgrade on Monday night. The parties demanded, among other things, Ružych’s resignation.

“As a responsible and well-educated person, as a professional in the performance of all public duties, as well as as a father and a citizen of Serbia, I made a rational decision to resign,” Ružić said in his resignation letter to Prime Minister Ani Brnabić . .

After the attacks, the government introduced a series of measures to prevent violence in schools and reduce the number of guns in civilian possession.

A 13-year-old boy opened fire at a school in Belgrade on Wednesday, killing eight students, mostly girls, and a security guard.

VIDEO Thousands of Serbs attended the funerals of the victims of two armed attacks this week