BILLERICA — Police Chief Daniel Rosa is alerting residents that the Billerica Police Department is looking for a man allegedly involved in a home invasion this afternoon.

Billerica Police received a 911 call at 12:22 p.m. from a Maplewood Avenue resident reporting the break-in at his home. The resident described the suspect as a tall, slender man wearing dark pants, a gray hooded sweatshirt and a mask. He was also reported as being armed with a knife.

The suspect immediately fled the residence after realizing that the homeowner was home. Officers responded to the area and established a perimeter. The Chelmsford, Burlington and Wilmington police departments’ K-9 units arrived to comb the neighborhood while the State Police Air Wing searched overhead.

The Dutile Elementary School implemented a shelter in place order during the incident, and school buses were briefly delayed from leaving the area until police completed the search.

“This is an active and ongoing investigation, and we are aggressively searching for this suspect,” Chief Rosa said. “We will continue investigating this matter and searching for the suspect, but anyone with information is encouraged to call Billerica Police immediately.”

Residents with any information about the suspect should contact the Billerica Police Department at 978-667-1212.