A seconds-long earthquake near the Croatian capital Zagreb has left one teenager in a critical condition and 16 others injured.

Prime minister Andrej Plenkovic said the 5.3 magnitude quake was the largest to hit Zagreb in 140 years. The shakes damaged the city’s iconic cathedral and littered the streets with debris including falling slabs of concrete which crushed cars.

A 15-year-old teen remains in a critical condition after being found by an emergency services team under a collapsed building, according to Zarko Rasic, the head of the Zagreb Emergency Medicine Institute.

Another minor had been admitted with head injuries from a falling roof when the quake struck 6km north of the city.

Medical staff and volunteers evacuate a maternity hospital in Zagreb. Photo: Getty

“It lasted over 10 seconds. By far the strongest I have ever felt,” one witness told Al Jazeera, adding that it was followed by several aftershocks.

Soldiers wearing masks had been called in to help clean up debris as citizens were advised to remain outside their homes while continuing to practise social distancing amid potential aftershocks.  

“Earthquakes are dangerous but coronavirus is even more so,” health minister Vili Beroš said.

Croatian Prime Minister Andrej Plenkovic (L) and Croatian President Zoran Milanovic (R) look at destroyed buildings and cars in downtown Zagreb after the earthquake hit. Photo: Getty

So far, Croatia has reported at least 254 cases of the virus and one death.

“We will do our utmost to make the best estimate of what to do at the moment. There are protocols when it comes to an earthquake. But when it comes to an earthquake combined with the global pandemic, then it is a much more complicated situation,” Interior Minister Davor Bozinovic said.

The city’s cathedral, which was rebuilt after it toppled in the 1880 earthquake, had one of its two spines collapse in the quake. Some buildings fell down as people fled apartments and took to the streets.

A picture taken on March 22, 2020 shows the dammaged tower of Zagreb’s Cathedral. Photo: Getty

The Zagreb Fire Department said firefighting and rescue operations were ongoing at several locations.

GFZ downgraded the magnitude of the quake from an initial reading of 6.0.

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

-with AAP