FORT COLLINS, Colo. -- Authorities are offering rewards for tips leading to the arrest of weekend Fort Collins rioters.

"Crime Stoppers of Larimer County will pay money for tips that lead to the arrest of those people who were participating in the riot this past weekend in downtown Fort Collins," Former Fort Collins Mayor Ray Martinez, now a Crime Stoppers board member, wrote in a Monday news release.

Martinez raised the possibility that police might post videos or still photos of rioters on the Internet, so the public can help identify rioters. But so far the police department has declined to release any riot images, citing its ongoing investigation.

Martinez's statement fumed with outrage over the early Sunday morning riot in the Old Town district when about 400 people threw bottles at officers, damaged cars, smashed shop windows and set fires following a festival and concert by Earth, Wind & Fire.

"This is more than 'just a riot' or an 'over-sized party.' It is a crime," the former mayor wrote. "We believe that when people are held accountable they are less likely to repeat their behavior."

"It is a crime to destroy property," Martinez wrote. "It is a crime to arbitrarily assault people. It is a crime to refuse to follow lawful orders of the police. And it is a crime to intimidate people."

Tipsters can anonymously call the Crime Stoppers hot line, 970-221-6868, or go to the group's webpage at www.stopcriminals.org.

Police say more arrests are possible. They plan to review video of the clash on Monday as well as review the various reports filed about the disturbance.

Rita Davis, spokeswoman for the Fort Collins Police Department, said the riot lasted several hours and caused significant damage to some businesses and vendor booths.

According to Davis, the crowd began getting out of control at around 1 a.m. near College and Mountain avenues. Davis said people in the crowd threw beer bottles, patio furniture and other objects at officers.

After being warned multiple times to disperse, Davis said SWAT members were brought in and tear gas and pepper spray were utilized to cow the crowd into order.

Police said two people were thrown through a window of a downtown shop and were taken to a hospital.