Sean Penn (search) has stepped into the shoes of a reporter once again.

The Oscar-winning actor has left a wake of excited fans and bewildered clerics around the Iranian capital while on a special assignment for the San Francisco Chronicle to cover Friday's presidential elections.

Last week, Penn attended Friday prayers at Tehran University where worshippers gave the well-known chant of "Death to America." On Monday, he told an audience at Tehran's Film Museum that such cries hurt prospects for starting a dialogue between Iran and the United States.

His trip has offered Iranian photographers the rare taste of paparazzi-style celebrity hunting. Iran has a highly respected domestic film industry that has won countless international awards, but few Hollywood stars have visited since the Islamic Revolution.

Given a press credential by Chronicle Executive Editor Phil Bronstein, Penn visited neighboring Iraq in late November 2003, shortly before Saddam Hussein was captured. He wrote a series of stories for the newspaper.

Penn, 44, won a best-actor Oscar in 2004 for his portrayal of a grief-stricken father seeking revenge for his daughter's death in "Mystic River (search)," directed by Clint Eastwood.

His screen credits also include "I Am Sam (search)," "Sweet and Lowdown (search)" and "Dead Man Walking (search)."