Montgomery County police investigate a shooting death Thursday in Gaitherburg. (Dan Morse/The Washington Post)

Montgomery County police said a man was fatally shot in Gaithersburg on Thursday afternoon, and officers searched into the night for two men believed to be involved.

Friday morning, the authorities identified the man as Michael Kirby Alvarado, 25, of Gaithersburg.

Officers were called to the 400 block of North Summit Avenue at 2:28 p.m., said Angela Cruz, a Montgomery police spokeswoman. Alvarado was found outside a three-story apartment building, she said.

Police dogs and a Maryland State Police helicopter were called in to help with the search for the men thought to be involved in the killing. One was wearing all black, and the other was wearing a black-and-white striped shirt, police said.

Montgomery school officials said that students and staff at Washington Grove Elementary School, Gaithersburg Elementary School, Forest Oak Middle School and Gaithersburg Middle School were held inside the schools — the doors were locked and no one was allowed to enter or leave — while police cleared the area. Forest Oak’s principal, Art Williams, wrote to parents that dismissal was delayed “as a precaution to ensure the safety and security of our students and staff.”

School officials said that all schools were cleared for dismissal by 4:30 p.m.

Residents of the Streamside Apartments, the site of the shooting, said their community generally is safe.

Tiffany JonesIngram, 24, said burglars kicked down the front door of her apartment three weeks ago. “It’s nice, but it has its days,” she said of the apartment complex.