PRAGUE (Reuters) - The police are searching for an American man suspected of killing four members of a family in the Czech Republic's second-largest city Brno, the police said on Thursday.

Police spokesman Petra Vedrova said the suspect may be armed and dangerous. The police have taken measures to stop him from leaving the country and were in contact with neighbouring states.

"(The suspect) goes by the name Kevin Dahlgren on social networks, lives in California and speaks only English," the police website said.

The victims were a family, but Ms Vedrova declined to give any further details. The American, who the police believe is 20 years old, is the only suspect.