(ANSA) - BELGRADE, APR 28 - Since mid-April, Croatia has been hit by an unprecedented wave of false reports of explosive devices: schools, nursery schools, shopping malls, newsrooms, hospitals and municipal offices have received hundreds of anonymous emails containing attack threats. All of the alerts were false, but they forced authorities to evacuate dozens of buildings and deploy bomb squads and law enforcement, disrupting normal school operations. According to Croatian media estimates, over 500 reports have been received in the last seven days, with daily peaks of 130 alerts in Zagreb, Dubrovnik, and Rijeka alone. These alerts were sent from encrypted addresses using grammatically incorrect Croatian emails. Interior Minister Davor Božinović referred to the phenomenon as "hybrid warfare," citing precedents in Serbia, Bosnia and Herzegovina, Montenegro, and North Macedonia. (ANSA).