SAN LEANDRO -- Police are investigating a home-invasion robbery in which three masked men broke into a home and robbed five residents -- including an 11-year-old child -- at gunpoint.

One resident, a man, was injured during the home invasion that took place early Friday morning.

Officers responded to a 2:30 a.m. armed robbery call at a home in the 1800 block of Marineview Drive, said Lt. Randy Brandt.

The victims, three males and two females ages 11 to 70, told officers that three masked men wearing dark clothes entered the home through a window, pointed guns at them and demanded cash.

During the incident, one of the robbers struck one of the male victims, Brandt said.

Police are not releasing where the victim was struck but did say he was not seriously injured.

The men stole what police described as personal property, then ran from the home.

"This was a violent act in a very quiet neighborhood," Brandt said. "Citizens need to pay attention to suspicious activity and report it to our police department immediately."

Anyone with information about the robbery can call police at (510) 577-3233.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.