The earthquake was registered at 11:19 GMT. Its epicentre was located 46 kilometres (28.5 miles) from the Croatian capital of Zagreb, at a depth of 10 kilometres.
The city's authorities called on firefighters and rescuers from all over the country to come to Petrinja, as many houses had been destroyed.
According to the latest data, at least 7 people were killed due to the earthquake, while rescue operations are still underway.
The earthquake is said to be the worst to hit the country in 140 years.
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© AP Photo
Croatian Prime Minister Andrej Plenkovic, centre, points as he stands next to an elderly woman who was evacuated because of an earthquake in Petrinja, Croatia, Tuesday, 29 December 2020.
Firefighters arrive after an earthquake in Petrinja, Croatia, 29 December 2020.
Police officers secure the area after an earthquake in Croatia, 29 December 2020.
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© AP Photo
Soldiers inspect the remains of a building damaged in an earthquake in Petrinja, Croatia, Tuesday, 29 December 2020.
Patients and medical staff are evacuated outside the Sveti Duh Hospital after an earthquake in Croatia, 29 December 2020.
A man walks over debris after an earthquake in Croatia 29, December 2020.
Destroyed houses and a car are seen on a street after an earthquake in Petrinja, Croatia, 29 December 2020.
A man stands on a street next to destroyed houses on a street after an earthquake in Petrinja, Croatia, 29 December 2020.
A grab of a video taken and released by the Croatian Red Cross on 29 December 2020 shows people looking through the rubble and rescuing victims in the streets of Petrinja after the town was hit by an 6.4-magnitude earthquake.
A destroyed car is seen on a street after an earthquake in Sisak, Croatia 29 December 2020.
