There are reports of at least 12 deaths and 50 casualties after a shooting incident at a premiere of Batman - The Dark Knight Rises in Denver, Colorado.
Witnesses have said a single attacker wearing a gas mask opened fire and set off some kind of device, perhaps a tear gas bomb or smoke bomb, and police say they now have one suspect in custody.

A man was arrested in a car park nearby in possession of a rifle and hand-gun. He told police that explosives were stored at his home, and an apartment block in the north of Aurora had been evacuated as a result.

A witness told 9News that during a shooting scene in the film he heard loud bangs and a lot of smoke and initially thought they were live special effects put on by the cinema.

CNN quoted one witness saying: "A guy slowly making his way up the stairs and firing - picking random people."

Projectiles came through the wall from the neighbouring theatre screening, the witness said.

Police chief Dan Oates has told reporters:
"Witnesses tell us he released some sort of canister. They heard a hissing sound and some gas emerged and the gunman opened fire," the police chief said.
"The shooting apparently went on for some time," he said.
Ten people were killed at the cinema and four others died later at hospital of their wounds.

President Obama has said in a statement that he and First Lady Michelle Obama are "shocked and saddened by the horrific and tragic shooting in Colorado".
He added: "We are committed to bringing whoever was responsible to justice, ensuring the safety of our people, and caring for those who have been wounded.
"As we do when confronted by moments of darkness and challenge, we must now come together as one American family."