Iran's Revolutionary Guards denounced President Mohammad Khatami in a letter published yesterday in Tehran, saying his moves to greater democracy were leading the Islamic republic into "anarchy".
But Dr Khatami said the "top secret" letter had been intended for his eyes only, raising fresh suspicions of a political power struggle as his student supporters claimed conservatives had staged last week's riots to topple him.
"How long do we have to be subjected to this trial run of democracy, which has turned into anarchy and puts the Islamic regime at risk?" said 24 senior Guards commanders in the letter, which was widely published in newspapers.
"How long do we have to stand by idly watching, with extreme sadness, what is happening in the country?" they said, threatening to take matters into their own hands.
"Our reservoir of patience is running low. And if nothing is done we could not accept that," they said.
The President, in the midst of a vicious political battle over his reform policies that has intensified since the riots, said the letter had never been intended for publication.
In a statement to the official IRNA news agency, Dr Khatami said it was a "top secret" state document and named the conservative Kayhan daily, which first released it on Monday, as responsible.
Pro-Khatami students added to the charges of political manoeuvring yesterday, directly accusing conservatives of orchestrating last week's violence in a bid to seize full control of the government.
A leading pro-reform student group, the Office of Consolidation and Unity (OCU), said conservatives were trying to portray Dr Khatami as a powerless head of state and "bring reform to a dead end."
It said the extent of damage from the unrest, which spread quickly from Tehran University throughout the capital, showed students could not possibly have been responsible.
"Everything was suspect from the beginning. From the extent of the damage throughout Tehran and the speed with which it was carried out, it could not possibly have been the work of students," an OCU spokesman, Mr Ali Afshari, said.
He said Dr Khatami still had the full support of students and warned it would be disastrous for the nation if conservatives succeeded in blocking his reform initiatives.
"Khatami is the last chance for the Islamic regime. His reform programme is the only way the Islamic republic can survive. If it fails, future generations will turn to non-peaceful means to achieve their goals," he said.
The unrest began after a hardline court closed down a popular reform newspaper, but the regime continued its press crackdown yesterday, arresting a senior employee of another pro-Khatami daily.
A senior editor with the moderate Sobh-e-Emrouz newspaper was jailed and charged with publishing an article "offensive to the Koran," IRNA said.
The arrest is the latest in a series of efforts to muzzle the largely pro-Khatami media, the President's most effective counterbalance against the conservative-dominated judiciary, police and parliament.