Jake Gyllenhaal got so angry about chipping a tooth on the set of his latest movie that he beat up one of his co-stars.

The handsome actor, who is romancing Kirsten Dunst, has confessed he turned violent after losing his temper while filming Gulf War drama 'Jarhead'. Jake even admits it took a whole month before his unfortunate victim, who he does not name, forgave him for lashing out.

He revealed: "For some reason, I just got so angry that I had chipped my tooth, and just started hitting him and we didn't talk for a month after that."

However, director Sam Mendes, who is married to Kate Winslet, has defended Jake, saying a lot
of tempers were frayed because of the tough filming conditions.

He told Calgary Sun newspaper: "It's 115 degrees, you're away from trees, cars, everything. You can't hear anything because the wind's blowing. You don't have your clothes, your car, your girlfriend, anything. And I really think Jake forgot he was acting a lot of times."

The movie, which is based on the memoirs of former Marine Anthony Swofford, was shot in the Imperial Valley in Southern California, which features geographical conditions similar to those in Iraq.