A well-known Bulgarian author of books about organised crime has been shot dead in the capital Sofia.
Georgi Stoev, 35, a former bodyguard, was shot in the head in front of a hotel and later died of his wounds.
The shooting came just hours after Borislav Georgiev, the head of an energy firm that maintains the Kozlodui nuclear plant, was shot dead in Sofia.
The EU has urged Bulgaria's government to do more to tackle organised crime and corruption.
The EU has already frozen some of its infrastructure subsidies for Bulgaria.
The EU imposed a special corruption monitoring scheme on Bulgaria and its neighbour Romania when they joined the EU in January 2007.
Mr Stoev had published a series of books about the role of the Bulgarian mafia after the collapse of communism in 1989.
He was hit by a single bullet and taken to hospital for emergency surgery but doctors were unable to save his life.