Four people, including an armed suspect, died during an hours-long police stand-off at a Colorado house.

The shootings occurred about four miles south-east of the Aurora Mall, where 12 people were killed and dozens wounded by a gunman at a midnight showing of the Batman film, The Dark Knight Rises, on July 20. The man charged in that shooting, James Holmes, goes to court tomorrow for a preliminary hearing in which prosecutors will lay out their case against him.

An Aurora police department special weapons team responded after shots were heard at the house at 3am, said Aurora police Sergeant Cassidee Carlson. Investigators said three people, all adults, appeared to have been killed before officers arrived.

The suspect shot at police five hours later and was killed during a shootout when officers stormed the house home about 45 minutes later, Carlson said. It wasn't known if officers shot the suspect or if he shot himself.

A fifth person escaped unharmed before officers arrived and reported that she saw three people inside the home who "appeared lifeless," Carlson said.

A motive for the killings was unknown.

Officers evacuated neighbours during the stan-doff and used a bullhorn to communicate with the gunman, urging him to surrender.