Sofia, Oct 8 (IANS): Bulgarian authorities have launched a probe into the rape and murder of an investigative journalist in the city of Ruse, the third journalist to have been killed in the European Union (EU) this year.

According to Bulgarian state media, the body of 30-year-old Viktoria Marinova was found on Saturday near a pedestrian alley in an area with heavy vegetation, CNN reported on Monday.

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

Bulgarian Interior Minister Mladen Mladenov on Sunday described the murder as "exceptionally brutal" and said Marinova was raped before she was killed.

He said the country's top murder investigators had been sent to Ruse to work on the case.

Ruse Regional Prosecutor Georgi Georgiev told the state media that Marinova's mobile phone, car keys, glasses and part of her clothing were missing when her body was found.

It remains unclear if Marinova's murder was related to her journalistic work.

The state media said that over the last year, Marinova had reported for the broadcaster TVN on an ongoing investigation into alleged corruption involving EU funds, CNN said.

She also worked on a programme focusing on social issues and was involved with charity work.