TEHRAN — In a furious series of Twitter posts and statements on his website Tuesday, Iran’s supreme leader called President Trump “psychotic’’ and repeated accusations that the United States bore primary responsibility for instigating a week of protests that rocked Iran in recent weeks.

“He says that the Iranian government is afraid of US power,’’ the supreme leader, Ayatollah Ali Khamenei, said of Trump. “So, if we are ‘afraid’ of you, how did we expel you from Iran in the late 1970s and expel you from the entire region in the 2010s?’’

Khamenei, who admitted that the recent protests, where people shouted harsh slogans against him, had hurt Iran’s establishment, threatened the United States with revenge.

“They damaged us during these days, they know there will be some sort of retaliation,’’ he said. “This man who sits at the head of the White House — although, he seems to be a very unstable man — he must realize that these extreme and psychotic episodes won’t be left without a response.’’

Protests took place in more than 80 cities nationwide, first over economic concerns but later broadening into a general critique of Iran’s clerical establishment.

Officially, 21 people have died and 1,000 were arrested, although a Parliament member from Tehran, Mahmoud Sadeghi, said Tuesday that 3,700 protesters had been arrested.

The uprising appears to have largely died down following a crackdown and the imposition of severe restrictions on social media.

However, protests reportedly flared in the city of Ahvaz on Monday night, a resident said in a telephone interview, as demonstrators and security forces clashed inside the city. The resident asked not to be identified for fear of reprisals.

In Arak, a city that has seen numerous protests, a local prosecutor, Abbas Qassemi, told the Mizan news agency Tuesday that an inmate had killed himself in a detention center.

“There is evidence on the body showing that the man had stabbed himself,’’ said Qassemi, who did not identify the man or provide video evidence. “Moreover, the footage of the moment he committed suicide is available.’’

On Monday, human rights advocates reported that a young peddler by the name of Vahid Heydari, who was arrested on New Year’s Eve, had died in what the prosecutor called a suicide in a detention center in Arak. It is unclear if this was the same person.

Human rights advocates and many Iranians have raised doubts about these official reports of suicides, saying the protesters had died while in custody but not by their own hand.

Such was the case with Sina Ghanbari, 23, who officials say killed himself inside Tehran’s Evin prison, known for its harsh conditions and treatment of prisoners, and where many protesters are being held.

A popular actress, Mahnaz Afshar, repeating popular sentiment, responded on Twitter, saying the death was unacceptable.

Others accused prison officials of having injected Ghanbari with an overdose of methadone, though they could not cite any evidence. It is unclear whether he participated in the protests or was arrested for something else.