Some anti-establishment protests happening in Iranian cities have turned violent, video footage shows.
They began three days ago - initially in protest at falling living standards - and are the biggest show of dissent since huge pro-reform rallies in 2009.
Demonstrators have ignored a warning by Iran's interior minister to avoid "illegal gatherings".
Two demonstrators are reported dead in Dorud after sustaining gunshot wounds in a video posted on social media.
Videos filmed elsewhere in the country show protesters setting fire to a police vehicles and there are reports of attacks on government buildings.
The current protests began in Mashhad on Thursday over living standards and rising food prices, and by Friday had spread to several major cities.
The Iranian authorities are blaming anti-revolutionaries and agents of foreign powers for the outbreak.
In the town of Abhar in northern Iran, demonstrators have set fire to large banners bearing the picture of Iran's Supreme Leader Ayatollah Ali Khamenei.
Meanwhile in Arak in central Iran, protesters have reportedly set fire to the local headquarters of the pro-government Basij militia.
In the capital Tehran, large numbers of protesters gathered at Azadi square. A senior Revolutionary Guards' figure in Tehran said the situation in the city was under control.
There are also numerous reports of people losing internet access on their mobile phones.
Iran is a key provider of military support to the government of Bashar al-Assad in Syria. It is also accused of providing arms to Houthi rebels fighting a Saudi-led coalition in Yemen, which it denies, and is an ally of Lebanon's powerful Shia movement Hezbollah, reports BBC.
The US State Department has urged all nations "to publicly support the Iranian people and their demands for basic rights and an end to corruption".