Five organisations, including the Paris-based Reporters Without Borders (RSF), said journalists and media institutions seeking to report independently on the island's Tamil separatist conflict were being "attacked and intimidated."
Following a fact-finding mission to Sri Lanka this month, the panel said in a joint statement that they found a deterioration in the press freedom situation since their last visit in June 2007.
It was "marked by a continuation in murders, attacks, abductions, intimidation and harassment of the media," they said.
In the recent World Press Freedom Index published by RSF, Sri Lanka was given the lowest press freedom rating of any democratic country worldwide, they noted.
"In recent months, journalists and media institutions seeking to report independently on the ongoing conflict have been attacked and intimidated in a seeming effort to limit public knowledge about the conduct of the war and to reveal their sources.
"This is a violation of the public