Tehran/Berlin - Iranian state television reported Sunday that there were 13 dead in Saturday's street clashes between government security forces and opposition demonstrators.

In some of the first details emerging to the outside world- amid an ongoing official clampdown on press reporting - reports also said that two petrol stations were burned down and that a military barracks had been attacked.

The clashes had followed warnings from Supreme Leader Ayatollah Ali Khamenei on Friday that any further opposition protests against the outcome of the June 12 presidential elections would be met with harsh measures.

According to eyewitness accounts, some 3,000 people took to the streets in Tehran on Saturday.

President Mahmoud Ahmedinejad was declared the winner of the June 12 election, but the opposition rallying around defeated presidential candidate Mir-Hossein Moussavi has contested the outcome, charging election fraud and demanding a new vote.

Moussavi on Saturday vowed again to press ahead with efforts to have the vote rerun.

"I will continue my efforts to clarify the truth on the basis of the constitution and current laws, although the violations and planning of this disgusting move had been planned in advance," he said to Iran's Guardian Council in a letter, a copy of which was obtained by the German Press Agency dpa. (dpa)