The Serbian government, which is building up its military, has reintroduced classes on defense and security to its high schools almost three decades after abolishing them.

The first classes were organized by defense ministry lecturers at a Belgrade high school, the ministry said in a statement Tuesday.

“We are tackling topics about Serbia’s system of defense and security, the army, about how to become an officer, about chemical, biological, radiological and nuclear defense,” the statement quoted Colonel Dragan Stojcic as saying.

During Communist rule in the former Yugoslavia, such courses were compulsory in schools and universities and included ideological propaganda and basic weapons handling.

After Yugoslavia collapsed in warfare in 1991, Serbia abolished such lectures a year later. It also ended compulsory military service in 2011.

Last August, President Aleksandar Vucic suggested Serbia might reintroduce compulsory military service to help improve the combat readiness of its army.

Under its 2019 budget, Serbia allocated $907 million, or 1.75 percent of gross domestic product (GDP), for its 40,000-strong military, up from $703 million in 2018.

It has also bolstered its air force with 10 MIG-29 fighters donated by Russia and Belarus and the purchase of nine helicopters made by Airbus.

Vucic and Defense Minister Aleksandar Vulin have often spoken of procuring more tanks, helicopters and armored personnel carriers from Russia.