An attacker or attackers threw suspected petrol bombs at the house of Czech Defence Minister Martin Stropnicky on Sunday, starting a small fire but injuring no one, media and his ministry said, according to Reuters. Stropnicky, who was not there at the time, said the attack pointed "to the radicalisation of certain groups, which stand against the values we hold," without going into further detail. Members of Stropnicky's family were inside when bottles containing liquid hit the house in a suburb of Prague, said police. Police did not say who they suspected. The force said in May it had uncovered a plot by a group of leftist militants to throw a large petrol bomb at a train. The Pravo daily newspaper reported Stropnicky had received a number of threats recently, citing unnamed sources. A small fire was extinguished quickly, it added. A ministry spokesman said authorities had waited to report the incident until police had finished an investigation at the scene. "Such things do not happen often on the Czech political scene. For me, it actually confirms that the ministry is on the right course," said Stropnicky in a statement late on Monday.