The body of a Congolese journalist was found on the bank of the Ngezi River near the provincial capital of Bunia in eastern Congo, the city's mayor said Saturday.

"We found his body yesterday in an advanced state of decay. It showed signed of strangulation according to the doctor who examined him on the scene. We couldn't move him further as it was very decomposed and had to bury him near the river," said Mayor Ferdinand Fimbo.

Guylain Chanjabo, a journalist at Radio Canal Révélation in Bunia, had disappeared 12 days ago. His body was found by people strolling alongside the riverbank.

The police have opened an investigation into the killing, said the mayor.

Chanjabo's death is the most serious of a growing list of abuses committed against journalists in Congo since the beginning of 2013. Over 54 cases of violation of press freedom have been recorded between January and the end of April by Journalistes En Danger (JED), a Congolese group campaigning for journalists' rights.

"Cases of abuse and intimidation of journalists have increased. It's intolerable," said Tuver Wundi a JED member in Goma. "The death of this journalist in Bunia is very serious."

In 2012, the group documented a record number of cases with 184 cases of violations of press freedom, including 78 incidents of censorship and 59 arrests of journalists.

The already difficult situation for journalists was worsened by the start of the conflict between the Congolese army and the M23 rebels, a Tutsi-led rebellion allegedly backed by Rwanda and Uganda. Both the army and the rebels have tried to control the media by imposing restrictions on journalists' movement, prohibiting access to the opposing side or threatening journalists whose reports are deemed unfavorable.

Several journalists working in territory under rebel control have had to leave because of death threats.

"In March, the M23 had split in two factions and they were fighting each other. I was reporting on both sides and the rebels that were in Rutshuru center where I live did not like it. They made clear to me that I should stop talking to the other faction. And then I received death threats," said Evariste Mahamba, a journalist at the local radio station Radio Ushirika.

Mahamba left the area and went to Kinshasa, Congo's capital, and his family moved to Beni, a town in the east of the country, for their safety.

"I had to leave my family in Beni, I had to leave all our possessions behind. It's not a comfortable situation," said Mahamba.

The movement made public apologies to journalists but several do not feel safe enough to come back in the area.

Radio Okapi, a radio station funded by the United Nations, saw its signal cut by the Congolese authorities because the station had broadcast an interview with members of the M23 after the rebels had temporarily seized the strategic city of Goma. The authorities' excuse was that Radio Okapi had not provided the Congolese government with a schedule of its broadcast. The schedule is publicly available on the radio station's website.

"It was the first time in the history of the radio station that the signal was cut. We couldn't believe it," said Bernard Conchon, Radio Okapi's director.

With 15 million listeners every day, Radio Okapi is Congo's number one radio station. It is also the most balanced and professional and over the years it has become a lifeline for Congolese people looking for credible information. Despite being supported by the U.N., it is not completely immune to censorship and repression.

"We measured how fragile we are. We realized that Radio Okapi could be silenced," said Conchon. "It was a shock to understand that even the U.N. umbrella does not protect us fully."