A Roma party in Bulgaria has warned authorities not to blame two recent teen murders on Roma people.

Evroroma claim that the police know who killed 18-year-old Rositsa and her sister Kristina, 15.

The attackers are now outside Bulgaria, the party's Borisslav Daskalov has told a private radio.

Daskalov, who is the party's coordinator for Pazardzhik and a municipal councillor, warned his fellows would ask for the local police chief to resign, in case the police try to put the blame on the Roma.

There isn't an outstanding official version about the motives and the perpetrators of the double murder.

Rositsa and Kristina went missing in the end of January.

Early next month, they were found raped and beaten to death near the town of Peshtera.