Tehran, Iran - Iran has threatened Israel and the US with counterstrikes in the event of an attack in support of the nationwide protest movement against the Islamic republic's leadership.

Any US attack would lead to strikes on Israel and regional US military bases as "legitimate targets," Iranian Parliamentary Speaker Mohammad Bagher Ghalibaf told the Arabic broadcaster Al Araby, according to a Sunday post on X.

US President Donald Trump had shortly before assured participants in the ongoing mass protests in Iran of his support.

"Iran is looking at FREEDOM, perhaps like never before," he said. "The USA stands ready to help!!!" Trump wrote on his platform Truth Social, having previously threatened to "hit hard" if protesters are killed.

Citing US officials, the New York Times reported that Trump had been briefed in recent days on new options for military strikes in Iran. He is seriously considering making good on his threat to attack the country again, the paper reported. The 79-year-old last June ordered the unprecedented bombing of Iranian nuclear sites, in support of an unprovoked war started by Israel.

According to the US-based Human Rights Activists News Agency (HRANA), the number of people killed in the mass protests that have been ongoing for two weeks has risen to 116, and more than 2,600 additional people have been arrested.

Despite an almost complete internet blackout, now in its fourth day according to internet monitor NetBlocks, HRANA said there have been demonstrations in 185 cities across the country.

Reza Pahlavi, the son of the shah who was overthrown in the 1979 Islamic Revolution and who is in exile in the US, called for nationwide strikes in Iran and for additional protests on Sunday.

Pahlavi is, however, a relatively unpopular figure in Iran, where many protesters have rejected the prospect of foreign intervention.