Showing support for Iran’s government, people have taken to the streets of the Islamic Republic in rallies that state television says were spontaneous.
The clerical establishment is eager to reassert its authority after pro-reform protesters clashed with police in deadly demonstrations at the weekend.
At least eight people were killed.
Parliamentary speaker Ali Larijani called for the arrest and firm punishment of those who he said had “insulted religion.”
Hundreds have already been detained, prompting an international outcry. Iran has accused the United Kingdom of “interference” in state matters, summoning its ambassador and delivering a stern warning.
“If Britiain does not stop talking nonsense, it will get a punch on the mouth,” said Iranian Foreign Minister Manouchehr Mottaki.
A sister of Nobel Peace Prize winner Shirin Ebadi is among those arrested.
In his first comments on the protests, Iran’s President Mahmoud Ahmadinejad is quoted as saying they were a foreign-backed “nauseating masquerade.”