Working conditions have deteriorated in the Tamil-populated northern district of Jaffna since fighting erupted there between government troops and Tamil Tiger rebels, the Free Media Movement (FMM) said in a statement.
"At least seven media workers including two reporters have been killed since May 2006," the statement said, adding that one journalist was missing and the offices of three media outlets had been physically attacked.
"Murders, kidnappings, threats and censorship have made Jaffna one of the world's most dangerous places for journalists to work," the FMM said, referring to the government-controlled peninsula.
Dozens of reporters have also fled or abandoned their work due to a climate of fear, the rights group said.
President Mahinda Rajapakse's military offensive against the Liberation Tigers of Tamil Eelam (LTTE) has also led to abductions and extra-judicial killings, rights groups say.
At least 835 civilians were kidnapped in Jaffna district between December 2005 and