Dacic told a press conference that the operation will result in filing criminal charges against 60 persons.
He said that the operation has so far covered 560 primary and secondary schools, 37 catering facilities and 19 open spaces, that 232 flats have been inspected and 260 persons searched.
Narcotics have been found with 51 persons who were not students and six have been held in custody for unauthorised possession of drugs and weapons, he specified.
In schoolyards in Belgrade and Subotica seven hiding places for narcotics have been located, he said, adding that the police uncovered eight laboratories with over 260 marijuana plants in Krusevac, Prokuplje, Valjevo, Kragujevac and Novi Sad.
He stressed that the police seized three kilograms of cocaine, a certain amount of heroin, more than 500 pills of synthetic drugs and 16 cars, while two persons from central search warrants were also located during the operation.
The police also seized 10 pieces of firearms and cold arms, 800 pieces of ammunition and several thousands of Euros.
Dacic stressed that this police operation aims to protect children from drug dealers who are present in schools, a problem often pointed out by parents.
Police operation Mreza can be perceived as a continuation of operation Morava, during which several tonnes of narcotics were seized and almost 10,000 persons processed, he concluded.