An earthquake of magnitude 5.3 struck north of Zagreb, Croatia on Sunday, GFZ German Research Center for Geosciences said, damaging buildings and sending many people into the streets.

There were no immediate reports of injuries. GFZ said the quake struck at a depth of 10 kilometres and it downgraded the magnitude of the quake from an initial reading of 6.0.

"It lasted over 10 seconds. By far the strongest I have ever felt," one witness said, adding that it was followed by several aftershocks.

Two massive earthquakes (5.3 & 5.1) have just struck Croatia's capital #Zagreb during nationwide lockdown. No fatalities, massive damage, incl. Zagreb Cathedral spire. Thousands in the streets, trying bravely & desperately to keep distance as much as they can. Mom & sisters safe. pic.twitter.com/vd8K5H5Jsg
— Roko Rumora (@rokorumora) March 22, 2020

Croatia's seismologist Ines Ivancic said the tremor was strong but the immediate damage could not be assessed. She added that the internet was down in some areas.

A Reuters reporter on the scene saw a church bell tower damaged and people taking to the streets.

The Maternity Hospital in Zagreb this morning. 😢 https://t.co/pEI5pLMKwr
— Nedad Memić (@NedadMemic) March 22, 2020

Croatia's Interior Minister Davor Bozinovic appealed via his Twitter account to people in the streets to keep social distance among themselves as the country struggles to the contain coronavirus spread. So far, the country has reported 206 cases of coronavirus and one death.

The U.S. Geological Survey said the quake measured 5.4, while European Mediterranean Seismological Centre (EMSC) also reported 5.3 magnitude, followed by another 5.1 magnitude earthquake.