BRUSSELS, June 19 (UPI) -- Belgian authorities arrested three men in connection with terrorism, including charges of attempting to commit murder, following an overnight sweep.
Nine people arrested on Saturday have been released by the investigating judge, BBC reported.
Authorities conducted searches overnight in 16 municipalities, mostly around Brussels.
Belgian Prime Minister Charles Michel said security will stepped up at public events and urged the public to remain calm.
Belgian media outlets had reported earlier that militant Islamists may have been planning to attack the football fan zone in Brussels, an area where Belgium's games in the Euro 2016 tournament in France are screened.
Bombs killed 32 people at a Brussels airport and a metro station March 22.
The three men charged on Saturday were named as Samir C., aged 27; Moustapha B., 40; and Jawed B., 29.
The sweep was reportedly arranged due to fear of an imminent attack, USA Today reported.
All three arrested Sunday were Belgian nationals charged "as perpetrator or co-perpetrator, for having attempted to commit a terrorist murder and for participation in the activities of a terrorist group," the federal prosecutor's office said in a statement.
Belgian media outlets reported that four federal ministers, including the prime minister and Justice Minister Koen Geens, and their families are under increased police protection.
"We learned about that late yesterday that this close protection would happen. They say there are good reasons for that," Geens said.
