
Sri Lanka is already under heavy pressure to address rights issues after a U.S.-backed U.N. resolution was passed in March urging the country to prosecute war criminals.
The police Criminal Investigation Department (CID) on Friday raided and closed news websites srilankamirror.com and srilankaxnews.com, which operated from the same premises, arresting nine people including eight journalists attached to the websites.
The websites were accused of defaming Rajapaksa and reporting news in an "incorrect and vulgar manner", police said.
"The Heads of Mission of the European Union have noted with concern the action taken against the Sri Lanka Mirror and the Lankanews websites," the EU mission said in a statement late on Sunday.
"Any action intended to intimidate independent journalism and or limit freedom of expression is in contradiction to UN human rights standards."
The United States said it was closely following the case.
"We have raised on several occasions our deep concern over efforts to suppress independent news media, including the blocking of news websites, intimidation, and disappearances of journalists," the U.S. Embassy in Colombo said in a statement.
The Media Centre for National Security, which comes under the defense ministry and handles publicity for the military and police, said the websites had continuously been publishing incorrect information.
All the arrested journalists were released on bail on Saturday, but the websites' equipment including computers were still under investigation, police said.
In March, the government censored mobile news alerts about military or police.
Sri Lanka initially blocked news websites during the final phase of a 25-year war against separatists Tamil Tiger rebels, banning the rebels' main website in 2008.
(Writing by Shihar Aneez; Editing by Daniel Magnowski)