RICHMOND -- A 15-year-old boy was arrested on suspicion of having a submachine gun after a standoff at an Iron Triangle home Monday, police said.

Police said the boy ran into a home in the 900 block of 9th Street at about 4 p.m. after he saw a police officer.

The officer witnessed the boy pulling a gun from his waistband as he ran inside the home, according to police.

Officers swarmed the home and after a standoff the teen was taken into custody, police Sgt. Nicole Abetkov said. A loaded Uzi was found under a mattress in a bedroom of the home, according to police.

David DeBolt covers breaking news. Contact him in Richmond at 510-262-2728. Follow him at Twitter.com/daviddebolt.