A US movie theater canceled the screenings of the new Joker movie after a "credible" threat, police said.
The movie, starring Joaquin Phoenix as Batman's sadistic enemy, proved controversial for its portrayal of violence and there was an increase in fear of security surrounding its release.
The cinema in Huntington Beach, California, canceled two screenings late on Thursday after police were called.
The Huntington Beach Police Department said it received reports of a possible threat to the Century Theater at Bella Terra Mall and was treating it as "credible."
James Holmes killed 12 people during a 2012 Dark Knight Rises screening
The cinema reopened on Friday, police said, but declined to provide details of the threat.
Police from US cities, including New York and Las Vegas, intensified patrols in the movie theaters.
Phoenix plays Batman's sadistic enemy
Relatives of victims of a mass shooting in 2012 by a man who identified himself as Joker expressed concerns about the film.
Twelve people were killed and 70 injured in the attack during a screening of The Dark Knight Rises in Aurora, Colorado.
The assassin was dressed in full armor and armed with weapons, including an assault rifle.
Joker is directed by Todd Phillips and acts as an origin story for Joker.
Director Todd Phillips (left) and Joaquin Phoenix
Set in 1981, follows the failed comedian Arthur Fleck, who turns to a life of crime in Gotham City.
Warner Bros, the studio behind the film, defended it, saying "neither the fictional character Joker nor the movie is an endorsement of any kind of real-world violence."
The film, ranked 15th in the UK for "strong bloody violence," also features Robert De Niro, Zazie Beetz and Frances Conroy in supporting roles.
Joker is in UK theaters now.