Police suggest those who died were likely unhoused people occupying construction containers.
The fire broke out on Thursday in Brno, located 200km (125 miles) southeast of Prague. The victims are yet to be identified.
Police suggested those who died were likely unhoused people occupying construction containers in a new neighbourhood that is expected to be built in the coming years.
The fire engulfed about 12 containers on the edge of an apartment complex before being extinguished early on Thursday, Czech TV reported.
Rescue workers said they did not find any injured people. Police and firefighters are investigating the cause of the blaze, which could take weeks, they said.
“There was no one at the scene we could have helped,” said a spokeswoman for the rescue services.
Footage from the scene showed metal bars had been attached to the windows, which prevented escape.
‘Human tragedy’
Marketa Vankova, Brno’s mayor, called the incident “a big human tragedy” and thanked the firefighters who spent several hours fighting the blaze.
“I am very sorry for everyone who died in the tragic fire in Brno tonight,” Prime Minister Petr Fiala said on Twitter.
In 2020, a fire in an apartment building in Bohumin killed 11 people. Another fire in an abandoned building often used by unhoused people in Prague killed nine people in 2010.
