Emergency vehicles and police gather outside this suburban Denver movie theatre in which 14 people were killed by a masked gunman.

Around 50 others were wounded when the man opened fire on moviegoers at a showing of the new Batman film The Dark Knight Rises in Aurora.

The local police chief said a suspect had been arrested and there was no evidence of a second gunman.

The male suspect is thought to be in his early 20s and was carrying several weapons, including a rifle and a handgun.

He did not resist arrest.

A local Denver radio station said a figure in a gas mask set off a smoke or tear gas bomb before shooting erupted.

Police said 10 people were killed at the scene and four others later died in hospital.

Sunita Rappai, Reuters