The Iranian capital of Tehran on Tuesday witnessed dueling student protests at universities in the ongoing fallout over footage showing the burning of a picture of the Islamic Republic's founder.

State television has repeatedly shown images, ostensibly taken during opposition protests on Dec. 7, of unidentified hands burning the picture of Ayatollah Ruhollah Khomeini, a shocking actions for most Iranians.

Hundreds of students demonstrated at Tehran's Science and Technology University contending the images were fabricated by government agents to discredit the opposition, the reformist Web Site Mowjcamp reported.

Students in the protest carried pictures of both Khomeini, who remains widely revered, and opposition leader Mir Hossein Mousavi. Similar protests also took place in at Qom university, 65 miles south of Tehran.

The official Iranian news agency, meanwhile, reported some 700 pro-government students gathered at the Tehran branch of Azad University to protest the desecration of Khomeini's photo and were challenged by 100 pro-reform students.

The actions of the students reflect how a protest movement that began by rejecting President Mahmoud Ahmadinejad's June 12 re-election has evolved to a constant challenge to the country's ruling theocracy.

State TV on Tuesday also said there were pro-government demonstrations throughout the country denouncing the insult to the Khomeini.

Reformists, including former presidential candidate Mousavi, maintain that their supporters had nothing to do with the burning of the picture, which they say is being used by the government as an excuse for further crackdowns.

On Monday Tehran prosecutor Abbas Jafari Dolatabadi said authorities had arrested several people on accusations of being involved in destroying the image.

Dolatabadi also said on Tuesday said he was filing a lawsuit against two Web sites and their license holders for insulting Ahmadinejad, state TV reported.

The suits target the conservative Jahannews and Alef news Web sites, the report said. The president has frequently faced criticism from within his own conservative camp, where some see him as monopolizing power and handing posts to close associates.

The lawsuit appears to be part of a government crackdown on dissent launched amid the turmoil since June's disputed presidential election. The crackdown has mainly targeted pro-reform and opposition figures, who claim Ahmadinejad won the election by fraud.

Alef belongs to lawmaker Ahmad Tavakoli, who has often criticized Ahmadinejad and last year led a campaign against his then-interior minister, who resigned after it was revealed he had a fake doctorate from Britain's Oxford University.

Jahannews asserted in October that Ahmadinejad helped foment Iran's postelection unrest with his rhetoric against opponents.

Iran also has a long history of attacks on media. Authorities have banned hundreds of newspapers, magazines and Web sites and arrested dozens of journalists and bloggers since 2000.