"The main office of the website comprising the computer hall and the most precious and valuable library have been completely destroyed," Lanka-e-News said in its own report on the attack.
"For many days now, we learnt from neighbors, unknown men have been carrying out surveillance outside and making inquiries about staff. Last night a caller threatened me that I would be killed," said Bennet Rupasinghe, news editor of the widely read website.
"All this is because we have been posting stories critical of the government," he said.
The office was doused with petrol and set on fire, he said. A computer screen exploded, which alerted the neighborhood.
There was an earlier attack on the offices of the website last year when it was housed in Nugegoda, he said.
Last year, the editor of the website, Sandaruwan Senadheera, and his family fled to the United Kingdom after reported threats to his life.
"Since he was forced to leave, I have been facing a string of threats and intimidation for exposing corruption and reporting on matters disliked by those in high authority," Rupasinghe said.
The website's offices are now located in the Colombo suburb of Malabe.
President Mahinda Rajapaksa has ordered the "police to conduct an immediate investigation," spokesman Bandula Jayasekera told reporters.
Lanka-e-News said journalists have suffered "unprecedented" losses since the president came to power, including the killing of reporters and editors.
"It is well to note that under the President Rajapaksa regime, the free media had suffered most and sustained losses to persons and property on an unprecedented scale in the media history of Sri Lanka," the site said.
"Sunday Leader Editor Lasantha Wickremetunge and 13 media personnel have been killed since this government came to power. The Professional Journalists Association Secretary was abducted and his legs were broken. A Lanka-e-News political columnist went missing. Sirisa (a leading TV network) was attacked and a claymore bomb was hurled at it," the report said.
"This is the government's new media culture. No dissent is tolerated. These attacks, intimidation of journalists are government's response to any view or facts they (the government) dislike," Mangala Samaraweera, the media head of the main opposition United National Party (UNP), told CNN.
Samraweera is a former Media Minister and Foreign Minister in President Rajapaksa's government.
Several media organizations are due to meet Monday evening to voice their protests over the incident.
Colombo, Sri Lanka (CNN)
