(CNN) Bulgarian authorities are investigating the rape and murder of an investigative reporter in the northern city of Ruse, the third journalist to have been killed in the EU in the past year.

The body of 30-year-old Viktoria Marinova, who worked for broadcaster TVN, was found on Saturday near a pedestrian alley in an area with heavy vegetation, Bulgarian state media reported.

Preliminary investigations showed the cause of death was blows to the head and suffocation.

Bulgarian Interior Minister Mladen Marinov described the murder as "exceptionally brutal" and said Marinova was raped before she was killed, according to state media. He said the country's top murder investigators had been sent to Ruse to work on the case.

Vigil for murdered TV journalist Viktoria Marinova in Ruse, Bulgaria.

Investigators are working with a psychology team to produce a profile of the perpetrator but authorities have not yet identified a suspect.

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