LOS ANGELES (AFP) - Hollywood has expressed concern about Iran's crackdown on directors and actors and called on Tehran to release filmmakers detained last month. "The Academy of Motion Picture Arts and Sciences is deeply concerned whenever and wherever the rights of filmmakers are threatened," the group said in a statement Wednesday signed by several movie-making guilds. "The recent arrest of six Iranian filmmakers, the sentence of 'one year in jail and 90 lashes' to an actress just for playing a role in an acclaimed film, and the continued house arrest of Jafar Panahi, among others, is a situation that demands our serious attention," it said. "We join our colleagues around the world in calling unequivocally for these filmmakers' safety, release, and return to filmmaking." Iran has reportedly released two of six Iranian filmmakers arrested last month on accusations of working for the BBC Farsi-language service. In a separate case, a Tehran appeals court recently upheld a six-year jail sentence and 20-year filmmaking and travel ban against international award-winning Iranian director Panahi, his family told AFP on Saturday. Panahi, 51, was convicted last December over a documentary he tried to make about the unrest that followed the disputed 2009 re-election of President Mahmoud Ahmadinejad. More than a dozen directors or actors have been arrested and sometimes received harsh sentences in recent months for "propaganda" against the regime, including several documentary makers accused of giving a "black image" of Iran.