"The Zagreb Police Department will report on the event. I would refrain from calling it an act of terrorism since only one concrete tile was damaged. We'll see what the police will say," Ostojic told the press.

When asked if the explosion could be linked to two blasts that recently rocked the city's western section of Stenjevec, Ostojic said: "I can't link it to anything if the police have established no such link yet."

A concrete floor tile at the north side of the Ban Josip Jelacic monument was damaged in a minor explosion that occurred at 0225 hours Wednesday.