The Director General of the United Nations Educational, Scientific and Cultural Organization has added her voice to those expressing concern about the killing of a prominent Russian journalist in Dagestan last week.

In a statement released Tuesday, Irina Bokova said she condemned the murder of Khadzhimurad Kamalov Friday, a day dedicated to the commemoration of journalists killed in the line of duty in the Russian Federation. She added that his death dealt a severe blow to press freedom.

Earlier Tuesday, the U.N.'s Office of the High Commissioner for Human Rights warned Russian authorities that the killing of Kamalov will send a “chilling message” to journalists, in particular those seeking to cover human rights issues.

Kamalov, who founded the Dagestan weekly newspaper Chernovik, was known for his extensive reporting on alleged abuses by the police and other human rights violations in Dagestan. He was shot to death as he left the publisher's office in the city of Makhachkala.

The Office of the High Commissioner for Human Rights called on Russian authorities to conduct a thorough, transparent and independent investigation into Kamalov's killing and to bring the perpetrators to justice promptly.