The websites of Iranian opposition leaders Mir Hossein Mousavi and Mehi Karroubi have posted calls for new protests on Tuesday to demand their release from reported house arrest.
The call, posted on Kaleme.com and Sahamnews.org, was issued by the Coordination Council of the Green Path of Hope, an umbrella group backing the two leaders who steadfastly oppose President Mahmoud Ahmadinejad's government.
"We invite everyone to protest on Tuesday... against the continued restrictions and house arrest imposed on the movement's leaders," the group said in a statement posted on the two websites.
It said the protests would be held in key squares and streets of Tehran and provincial cities.
The group, which called previous protests on February 14 and February 20, said that more demonstrations would be held on March 15 if Mousavi and Karroubi remained under house arrest beyond March 1.
The February 14 protests were deadly with two people killed when clashes erupted between demonstrators and security forces. But the February 20 protests in Tehran were quelled by a massive deployment of police.
The two protests, the first to be held since February last year, infuriated the authorities who accused Mousavi and Karroubi of treason and put them under "complete" house arrest, according to opposition websites.
Officials have also branded anyone who supports the two men as "anti-revolutionary."
Mousavi and Karroubi led a string of protests in Iran after Ahmadinejad's controversial re-election in June 2009, which they claim was rigged.
Their opposition to Ahmadinejad has shaken the Islamic regime and divided the nation's elite Shiite clergy.