N1 also reported twenty injured locals of Petrinja had been transported to the Sisak hospital, with two seriously injured.
"We have hired the army to transport the sick," said Minister Vili Beros, who is in the Sisak hospital.
The roof of a building seen collapsed Credit: AFP or licensors Residents have been told to stay away from older buildings Credit: Twitter / tercbela Soldiers speak with one another amid rescue operations Credit: EPA A damaged BMW in downtown Zagreb Credit: Rex Features Despite a travel ban in place due to coronavirus, many attempted to flee the city of Zagreb.
Security cameras in the capital provided footage of parked cars shaking for several seconds, triggering security alarms.
Hospitals have also been evacuated in the immediate areas to ensure patient safety.
European Council President Charles Michel offered full EU support and said "our thoughts go out to the injured and frontline workers".
Images of the town, which is home to around 20,000, showed the huge devastation the earthquake has caused.
The tremor comes one day after a smaller earthquake struck Petrinja, causing some damage to buildings.
The Balkan region lies on major fault lines and is regularly hit by earthquakes.
The earthquake was felt in Zagreb, some 30 miles north of the epicentre Credit: Reuters Patients and medical staff had to leave the Sveti Duh hospital in Zagreb Credit: Reuters Damaged to a property in Zagreb Credit: Reuters Clean up crews move rubble in Petrinja Credit: AP:Associated Press The Red Cross described the situation on the ground as 'very serious' The quake caused the roofs of many buildings to collapse Credit: Twitter / tercbela Locals sift through rubble following the quake Credit: AFP or licensors