Three people have died and about 200 others have been arrested over the past few days in ethnic clashes in the south-west of Iran.
The clashes are thought to have been sparked by a letter, allegedly from the president's office, about changing the ethnic makeup of the area.
But Intelligence Minister Ali Younessi said the letter was a fake.
He said many of those arrested had ties to foreign groups or TV networks aiming to overthrow Iran's Islamic government.
He said these included innocent young people who had been deceived and provoked by secret agents.
On Saturday, three people were reported to have been killed when government offices and banks came under attack in the city of Ahwaz in Khuzestan province, which borders Iraq.
The clashes are believed to have been between the police and ethnic Arabs, who are the majority in Ahwaz though they make up only 3% of the population of Iran.