High-ranking officials from Bulgaria's National Revenue Agency (NRA) have received threats, while one of them had his family house torched, private Bulgarian television channel bTV reported on May 19 2010.It was not immediately clear who carried out the arson or who was behind the threats, but it was likely that NRA officials would be given personal security protection, the report said.The first threat was forwarded to Krassimir Stefanov, head of the NRA, and was followed by an attack on the house of Toshko Todorov, Stefanov's deputy, whose house in Dobrich was torched on the morning of May 19.The house belonged to Todorov's parents and was empty at the time.The police has launched an investigation, while Todorov himself told the authorities that he believed that the attack was related to his involvement in the law enforcement operation codenamed "Deceivers" a week earlier.Reportedly, this was the second such personal attack against Todorov. His house was fired upon in November 2005, when he was employed at the regional office of the revenue agency in Dobrich.On May 13, several "specialised police operations" were conducted overnight across Bulgaria aimed at tackling organised crime rings. The police raided one group suspected to be involved in human trafficking in the town of Razgrad. Allegedly, the people were exploited for labour. In operation "Deceivers", the police arrested five members of an alleged criminal operation that carried out numerous phone scams.