A long police standoff at a house in Aurora, in the US state of Colorado, has ended with four people dead, including the suspected gunman.

Aurora police were called to the scene after shots were heard in the area. They evacuated neighbors and tried to communicate with the gunman, urging him to surrender. They later stormed the house, but found the 3 victims had already been killed. Another person managed to escape unharmed.

The suspect died as police entered the house, although it's unclear if he shot himself or was killed by officers. An investigation is currently underway.

The shootings occurred just southeast of the Aurora Mall, where 12 people were killed by a gunman at a movie theater in July last year.