A Brazilian radio journalist has been shot and killed in his studio, with one rights group suggesting a political motive for the murder.

Gleydson Carvalho, a journalist in the town of Camocim, in the northeastern state of Ceara, was shot five times on Thursday at point blank range, according to authorities, who said the gunmen fled the scene on a motor bike driven by an accomplice.

"They arrived at the radio door. They said they wanted to announce something. Someone opened the door for them. They said it was an attack and asked who was in the studio," police chief Hebert Silva told the AFP news agency.

"Immediately after that, the individuals entered and executed Gleydson with three bullets to the head and two to the stomach."

A sound engineer present at the time of the shooting at Radio Liberdade was unharmed.

Fourth journalist

According to Human Rights Watch (HRW), Carvalho, who often criticised local politicians on the air and in social media, was the fourth journalist to be killed in Brazil this year. 

"The investigation should specifically take into account the likelihood that Carvalho was killed in retaliation for his work as a journalist," a report by the US-based group said.

"Attacks against journalists for their work threaten freedom of expression and the very fabric of democracy," said Maria Laura Canineu, Brazil director at HRW.

Security forces have identified a suspect and were searching the town and surrounding area for the gunman.

Police said they have arrested two people with ties to the main suspect in the case, and have recovered what they believe to be the murder weapon.

Threats

Several Brazilian media outlets have reported that Carvalho had received threats because of his work.

In May, Evany Jose Metzger, a blogger, was found decapitated in the state of Minas Gerais, and the body of another radio journalist, Djalma Santos da Conceicaos, was discovered on May 23, a day after he was kidnapped in Bahia.

Their bodies showed signs of torture. Both journalists were known for reporting on corruption, HRW said.

In March, a Paraguayan radio journalist, Gerardo Ceferino Servian Coronel, was shot dead in the Brazilian city of Ponta Pora, on the border with Paraguay.

Brazil is the third most dangerous country in Latin America for journalists, following Mexico and Honduras, with 38 journalists killed between 2000 and 2014, according to the nonprofit group Reporters Without Borders.

Source: Agencies