Obama, Romney sorrow over Denver
US president Barack Obama and his rival Mitt Romney today cancelled presidential campaign-style speeches and some ads attacking each other, replacing them with expressions of sorrow for the victims of a deadly shooting rampage in Colorado.
A gunman opened fire in a crowded movie theatre in the Denver suburbs early this morning, killing at least 12 people and wounding 50 others.
Mr Obama, briefed by aides early in the morning, was to return to Washington after addressing the incident during remarks at an event in Fort Myers, Florida.
The shooting erupted during midnight showings of The Dark Knight Rises at the multiplex in Aurora, Colorado, where throngs had gathered, some dressed as characters from the highly anticipated Batman sequel.
A federal law enforcement official said a suspect in the shootings, a man born in 1987, was in custody.
Police and federal agents were searching an apartment in the town after the man said he had explosives there. Other residents in the building were evacuated as a precaution.
"We're treating this as an active shooter investigation working with Aurora police," according to a statement released by the FBI.
Chaos spread quickly through the multiple packed theatres as the gunman, wearing a gas mask, stood in the front of one theatre at around 12:30am and began firing at the crowd, the Associated Press reported.
Witnesses described smelling either pepper spray or tear gas in the theatre as the gunfire rang out.
US president Barack Obama, who spent the night in southern Florida as part of a campaign swing, was notified of the shooting by his top counterterrorism adviser, John O Brennan, at 5.26am, according to the White House.
He later released a statement saying that he and the first lady were "shocked and saddened by the horrific and tragic shooting in Colorado," and vowed to bring those responsible to justice.
"As we do when confronted by moments of darkness and challenge, we must now come together as one American family," Mr Obama said.
"All of us must have the people of Aurora in our thoughts and prayers as they confront the loss of family, friends and neighbours, and we must stand together with them in the challenging hours and days to come."
Colorado television showed several ambulances moving about and dozens of police officers gathered at the Century 16 movie complex in the morning darkness.
A police robot could be seen inspecting a white compact sedan, its two doors and trunk wide open, in the parking lot of the movie complex, television images showed, though it was unclear whether the car belonged to the gunman.
"I saw a man walk in through the exit," a witness told a reporter from 9NEWS in Colorado, saying he threw what appeared to be a pair of gas canisters to the ground.
"He waited for both the bombs to explode before he did anything. Then, after both of them exploded, he began to shoot."
Mobile phone video appeared to show the traumatic scene outside of the large multiplex immediately after the shooting.
Some people wandered away with bloodstained shirts as other could be heard screaming, "Get out of here!"
A witness told CNN affiliate KUSA that he was in one of the other theatres showing the movie.
"It's crazy to think I could have been in the other line," he said.
"We were watching a scene of the movie - it was a shootout scene, there were guns firing," he said.
"Then loud bangs came from the right of the theatre. Smoke took over the entire theatre, and it was really thick and no one could really see anything. Me and my sister were sitting there wondering what was going on. Five people were limping, wounded, slightly bloody."
"I saw a girl who was pretty much covered in blood. It made me think the worst," the man said.
"A cop came walking through the front door, before everyone was cleared up and before everything was completely under control, holding a little girl in his arms, and she wasn't moving."
New York Times