Police investigating after fireworks reportedly set off inside Kamiak High School

MUKILTEO, Wash. -- Police are investigating after two loud pops were heard Monday morning at Kamiak High School in Mukilteo. School officials said nobody was hurt.

An official with the Mukilteo School District said it appeared that firecrackers were set off in a school stairwell around 9:30 a.m.

Mukilteo police said two loud bangs were heard. Officers found possible firecracker residue in the stairwell.

The lockdown was lifted around 1 p.m. Police said nobody was arrested and they were working to figure out who set off the firecrackers inside the school. They said it sounded like gun shots were going off.

Neighboring Everett Public Schools first tweeted about the incident, saying they were supporting staff at the Mukilteo School District while they handled the incident.