PRAGUE - Six people have been killed and two others heavily injured when a chemical plant exploded on Thursday morning in Kralupy nad Vltavou, a town in the north of Prague, said Czech regional rescuers spokeswoman Petra Effenbergerova.

Effenbergerova said the blast occurred after 10 am local time due to the explosion of an uncertain container at the site during disassembling of some construction. Emergency crew including helicopters rescued the victims to the hospitals of Prague.

Fire spokesman Petr Svoboda said the risk of further blasts has been identified and eliminated.

The Unipetrol factory spokesman Pavel Kaidl said that more information will come in the next hours. He also admitted that the explosion shall not cause any damage to the city and civilians as it's distantly located.

At the moment, a number of hospitals in the capital have been put on a high alert to meet any emergency if more injured would be reported later.

Czech President Milos Zeman and Prime Minister Andrej Babis have expressed their sincere condolences to the survivors of the explosion at the chemical company. Interior Minister Lubomir Metnar arrived at the site for further investigation.

The incident is considered to be one of the most tragical one happened at the industrial site in the Czech Republic since the 1960s.