Two people were killed and at least five others were injured in a mass shooting on Sunday at Seattle Center in the US state of Washington, according to the Seattle Fire Department.

A barrage of gunshots rang out around 6 p.m. at the center, where thousands of people had gathered for the Bite of Seattle food festival this weekend. 

Seattle Mayor Katie Wilson said in a statement that two people were taken into custody. Wilson condemned the shooting as an "act of horrific violence."

Police had not released information about whether suspects remained at large. No apparent motive for the shooting was disclosed on Sunday.

The fire department was quoted by The Seattle Times as saying that aid crews treated five other people at the scene: a 2-year-old boy, a 23-year-old man, a 39-year-old woman and a 56-year-old woman, all of whom were taken to the hospital. A woman, 40, suffered minor injuries.

Bite of Seattle, which has taken place at Seattle Center for decades, is one of the busiest annual events at the venue. The event featured hundreds of food and retail vendors as well as live music.