At least 40 people were injured in a large explosion at a building in Czech Republic's Prague city on Monday, officials said.
The police evacuated the National Theatre and other neighbouring buildings following the explosion on Divadelni Street.
The police have sealed off the area.
The police said they suspect that the explosion was caused by a gas leak.
No casualties have been reported so far.
"We heard a strong explosion and we felt the building tremble and the windows shake," eyewitness Jaroslav Faltus told BBC.