Hollywood film-makers including Steven Spielberg and Martin Scorsese have called on the Iranian government to release director Jafar Panahi.

A petition also signed by Robert De Niro, Robert Redford and Francis Ford Coppola, denounced the arrest of Panahi on 1 March.

"We... stand in solidarity with a fellow film-maker", the petition read.

Panahi, known for his social realism, has made several films critical of Iran's regime.