5:55 GMT

A week ago a call for a silent protest in Tehran on June 12 (22 Khordad) from 6pm to 8pm, was made by the Coordination Council of the Green Path of hope, a group linked to opposition leaders Mir Hossein Mousavi and Mehdi Karroubi.

There have been expressions of disappointment, and a sense that under the current heavy security atmosphere a silent protest may not be very effective.

Amir Arjomand, senior advisor to Mir Hossein Mousavi, has attempted to provide the rationale for this decision.

Today, there are signs that activists in Tehran University are mobilizing for that day. The following video from a reliable source, shows posters on walls and drawing boards in Tehran University (purported), calling for a “Green” day: