Sean Penn turns into action hero in <em>The Gunman</em>

London - US actor Sean Penn, who won Oscars for his brooding ex-convict in Mystic River and a doomed gay rights leader in Milk, turns action hero in The Gunman - a thriller that had its world premiere in London on Monday.

Starring alongside Spain's Javier Bardem and Britain's Idris Elba, Penn plays a former assassin whose last job killing a politician from the Democratic Republic of Congo comes back to haunt him.