Bulgaria's prime minister says the Bulgarian authorities are still unable to confirm the identity of the suicide bomber who killed five Israeli tourists and a Bulgarian bus driver last week.
Boiko Borisov said investigators have been unable to match the fingerprints and DNA samples of the suicide bomber with databases around the world.
He said the suicide bomber had accomplices and may have entered Bulgaria from the European Union's visa-free Schengen travel area.
Borisov was speaking on July 24 at a joint press conference with John Brennan, U.S. President Barack Obama's Assistant for Homeland Security and Counterterrorism, who was on a visit to Sofia.
Bulgarian media reports have said police were investigating the involvement of two more people in the blast in the Black Sea port city of Burgas on July 18.
With reporting by dpa, AFP, and mediapool.bg