At least one person was killed and a city in central Croatia was left in ruins after a strong 6.4 magnitude earthquake Tuesday, according to the US Geological Survey and local officials.

The full extent of the victims was not known. There were reports that the quake, which occurred just after noon local time, about 30 miles from the capital, Zagreb, could be felt in the Balkans and as far as Hungary.

The epicenter of the quake was near the town of Petrinja, and the mayor Darinko Dumbovic told Croatian state television that at least one person, a 12-year-old girl, had been killed. He said he passed her body on the street.

“This is a disaster,” he said. “My city is completely destroyed.”

“We need firefighters, we do not know what is under the surface, a roof has fallen on a car, we need help,” he said in an emotional telephone interview from the scene that was broadcast on Croatian state television.

“Mothers cry for their children,” he said.

Images from the city on social media and local TV showed streets littered with rubble, buildings with collapsed roofs, and rescue workers looking for people who might be trapped.

In the moments after the earth stopped shaking, orange dust filled the air as car alarms went off, church bells rang, and calls for survivors rang through the streets.

In a dramatic rescue, a man and a child were pulled from a car buried under rubble. The mayor told local reporters that he did not know the condition of the two people, but that they appeared to be alive.

“I also heard the kindergarten collapsed,” he said, adding, “Fortunately, there were no children in the building at the time.”

The Red Cross in Croatia said it was a “very serious” situation.

The earthquake was the second to hit the area in two days after a 5.2 magnitude tremor on Monday morning damaged buildings and fueled fears in a region with a history of seismic activity.

It took only a few hours for Prime Minister Andrej Plenkovic and President Zoran Milanovic to tour the center of Petrinja to investigate the damage caused by the first quake.

While that first tremor caused no injuries, Mr Dumbovic said many buildings had been damaged, which left them in a precarious state when the second quake erupted.

He said there had been several small earthquakes in the past few days and that many residents were afraid to spend the night in their homes.

In Zagreb, where people took to the streets during the quake, many decided to ignore the current travel ban in order to limit the spread of the coronavirus and leave the city.

In neighboring Slovenia, the state news agency announced that the country’s only nuclear power plant, located about 100 km from the epicenter, has been shut down as a precaution.

The Hungarian Paks nuclear power plant said in a statement that it had not stopped production even though the earthquake was felt there.

Ursula von der Leyen, President of the European Commission, said she had asked Janez Lenarcic, the European Commissioner for Crisis Management, to be ready to travel to Croatia to provide assistance.

The region is prone to earthquakes and experts have warned that the Balkans in south-eastern Europe have not addressed the risks of aging buildings.

While many towns and villages trace their roots back hundreds of years, a building boom that happened in the 1990s during the transition from communism to capitalism often meant that structures were built without regard to safety standards.

The result is that millions of people are living in buildings that are unlikely to survive a major earthquake, experts say.

In Croatia, the scars of past quakes are still visible in places like Dubrovnik, where a quake in 1667 destroyed almost a third of the city and killed more than 5,000 people.

Alisa Dogramadzieva and Joe Orovic contributed to the coverage.