TEHRAN: Iran's Revolutionary Guards warned on Saturday that safeguarding security was a "red line" and the military vowed to protect public property, as the clerical establishment stepped up efforts to quell the most widespread protests in years.
The statements came after US President Donald Trump issued a new ​warning to Iran's leaders on Friday, and after Secretary of State Marco Rubio on Saturday declared: "The United States supports the brave people of Iran."
Unrest continued as state media said a municipal building was set on fire in Karaj, west of Tehran, and blamed “rioters.”

State TV broadcast footage of funerals of members of the security forces, it said, who were killed in protests in the cities of Shiraz, Qom and Hamedan.
A witness in western Iran reached by phone said the Revolutionary Guards were deployed and opening fire in the area from which they were speaking, declining to be identified for their safety.
In a statement broadcast ‌by state TV, the IRGC — an elite force which has suppressed previous bouts of unrest — accused terrorists ‌of targeting military ​and law ‌enforcement bases over the past two nights, killing several citizens and security personnel and saying property had been set on fire.
Safeguarding the achievements of the 1979 revolution and maintaining security was "a red line," it added, saying the continuation of the situation was unacceptable.
The military announced it would "protect and safeguard national interests, the country’s strategic infrastructure, and public property."
In a statement published by semi-official news sites, the military accused Israel and “hostile ‌terrorist groups” of seeking to “undermine ‌the country’s public security.”
On Friday, Supreme Leader Ali Khamenei said rioters were attacking public properties and warned that Tehran would not tolerate people acting as “mercenaries for foreigners.”
The Revolutionary Guards’ public relations office said three members of the Basij security force were killed and five wounded during clashes with what it described as “armed rioters” in Gachsaran, in the southwest.
Another security officer was stabbed to death in Hamedan, in western Iran. 
The son of a senior officer, Brig. Gen. Martyr Nourali Shoushtari, was killed in the Ahmadabad area of Mashhad, in the northeast. Two other security personnel were killed over the past two nights in Shushtar, in Khuzestan province.
Authorities have ‌described protests over the economy as legitimate while condemning what they call violent rioters and cracking down with security forces.
Iranian rights group HRANA said it had documented 65 deaths, including 50 protesters and 15 security personnel as of January 9. 
The Norway-based human rights group Hengaw said more than 2,500 people had been arrested over the past two weeks.
A doctor in ⁠northwestern Iran said that since Friday, large numbers of injured protesters had been brought to hospitals.