Police cordon off part of central Prague following an explosion that injured as many as 40.<br/> <br />Witnesses say around a dozen people were treated at the scene by emergency services.<br/> <br />The blast, probably caused by gas, came from a building owned by Czech Air Navigation Services.<br/> <br />Police said about 15 people were in the building at the time of the explosion.<br/> <br />Many surrounding buildings were evacuated, including the National Theatre.<br/> <br />This pensioner says she heard an incredible explosion and thought her building would collapse.<br/> <br />The fire department says there are no reports yet of fatalities.
