Czech police deployed armed guards in Prague's historic centre today after security services issued its most serious warning of a terrorist attack.
Prime Minister Mirek Topolanek said the government had met late yesterday and early today to adopt extra security measures.
Police deployed guards around dozens of buildings in the historic capital of 1.2 million, which is a magnet for foreign tourists. Armed police also patrolled central Prague.
"The government received information from representatives of the security services and police of an increased risk of a terrorist act on the territory of the capital, Prague, related to increased security risks of similar character abroad," Mr Topolanek said in a written statement.
"The government ... decided to strengthen security measures on the territory of the capital, Prague, with the aim of eliminating the existing risks," he added.
Interior Minister Ivan Langer said the threat was the most serious for the country of 10 million.
"This is the first time that the Czech Republic is facing, in such a concrete way, such a concrete heightened risk of a terrorist act," Mr Langer told a news conference. He said information on the possible attack was obtained through cooperation between Czech and foreign security services.
Mr Langer said the government did not have any further information about the threat.
The Czech Republic has a small military unit in Afghanistan and military police instructors in Iraq. It has not been a target of terrorist attacks in past years.