SOFIA: Explosions overnight Sunday at two nightclubs in the Bulgarian capital Sofia injured five people, three of them seriously injured, the interior ministry reported.

A blast at the Casablanca club left two men, aged 30 and 53, in critical condition, said the statement. Two women were also injured in the explosion.

A blast at a strip club, Pantera (Panther), seriously injured a 36-year-old man.

Bulgaria''s criminal underworld regularly uses bomb attacks as a means of settling scores with their rivals. An explosion on Tuesday evening near the capital''s law courts injured two people, who were reportedly trying to set the bomb in front of lawyers'' offices.

Bulgaria, which joined the European Union in 2007, has been regularly criticised by Brussels for its failure to take more effective action against crime and corruption in the country.