COLORADO - A masked gunman shot dead 14 people and wounded 50 others at a showing of the new Batman movie "The Dark Knight Rises" at a movie theatre in the US city of Denver, the local police chief told CNN.
Denver's KOA radio station said a figure in a gas mask had opened fire at the late-night showing in a mall in the suburb of Aurora and set off a smoke or tear gas bomb.
Dozens of police were at the scene, and the authorities evacuated the area while they checked if there was an explosive device in the area.
CNN quoted one witness as saying he saw a "guy slowly making his way up the stairs and firing, picking random people".
It said local hospitals were alerted to a "mass casualty incident".
Media reports said 10 people died at the scene and four died later in hospital.
A spokesman for Denver's Swedish Medical Centre said three people had been admitted to hospital with gunshot wounds and were in critical condition.
Another hospital, Denver Health, had received six wounded, one of whom was in critical condition, spokeswoman Kalena Wilkinson said.
A witness told CNN: "We heard anywhere from 10 to 20 shots and little explosions going on. Shortly after that we heard people screaming. Then they came on the PA system and said everyone needed to get out.
"As soon as we got out, there were people running around and screaming." He said friends had told him the gunman was wearing a gas mask.
Another witness said the gunman opened fire during a shoot-out scene in the movie, leading to confusion. The theatre also filled with thick smoke, he said.