The move follows a government ban on broadcasts of the film by Geert Wilders, leader of the Dutch anti-immigration Freedom Party, which alternates images of the September 11, 2001 attacks and other Islamist bombings with quotations from the Koran.
The information ministry spokesman said telecommunication firms PT Telekomunikasi Indonesia, PT Telekomunikasi Selular, and PT Exelcomindo Pratama, and Internet provider Indonet had
Telekom had also blocked social-networking site MySpace and is still looking for other sites and blogs that have posted the film to block them, Eddy Kurnia, vice president for public and marketing communication, said in a statement.
Wilders' film urges Muslims to tear out "hate-filled" verses from the Koran and starts and ends with a cartoon of the Prophet Mohammad with a bomb under his turban, accompanied by a ticking sound.
The film has sparked protests in Indonesia, the world's most populous Muslim nation and a former Dutch colony.
President Susilo Bambang Yudhoyono has urged his predominantly Muslim nation not to use violence in protests against the film.
The Dutch government has distanced itself from Wilders' views, and the Dutch upper house of parliament has condemned what it called efforts to denigrate Islam and promote hatred.