DENVER (AP) -- Two men accused of holding a hostage during a six-hour armed standoff at a RadioShack store in Denver have been formally charged.

Denver District Attorney Mitch Morrissey said Monday that 19-year-old Taveaun Williams and 23-year-old Michael Annan each have been charged with attempted first-degree murder, second-degree kidnapping, aggravated robbery, as well as with two sentence-enhancing counts of a crime of violence.

Investigators say the Sept. 7 standoff began as an attempted robbery and ended peacefully when the suspects released 28-year-old hostage Chris Nimerfroh and surrendered. Police Chief Robert White says one or both suspects fired a weapon during the standoff but no one was injured.

Williams and Annan remain in custody each on $200,000 bond.