"One of your defenders lost his life in defense of this community today. This was an unprovoked attack," said Prince George's County Police Chief Henry P. Stawinski.

WASHINGTON — Prince George’s County police say an officer died Sunday after being shot outside the department’s District III station in Landover, Maryland.

According to police, a preliminary investigation indicates that a suspect opened fire around 4:30 p.m. in the area of 7600 Barlowe Rd., next to Prince George’s County police headquarters. Police Officer First Class Jacai Colson returned fire, and was shot.

Colson, 28, was taken to Prince George’s Hospital Center in Cheverly, where dozens of police officers joined hands to form a prayer circle outside the trauma center.

Officers are praying outside trauma center where officer shot taken pic.twitter.com/McKkwsAroG — Dick Uliano (@DickUliano) March 13, 2016

Police said Colson succumbed to his injuries at the hospital.

Roads were closed in the region and residents had been ordered to shelter in place for hours while police searched for the shooters. The advisory was lifted at around 7:30 p.m.

Prince George’s County State’s Attorney Angela Alsobrooks called the shooting an “act of cowardice” and a “horrific act of evil.” She promised an aggressive investigation and prosecution of the alleged shooter, who was wounded in the return fire but is expected to survive, and another suspect arrested soon after the shooting. Their names were not immediately released.

Colson, a four-year veteran, had been assigned to the department’s Narcotic Enforcement Division, police say. He would have turned 29 years old this week.

“One of your defenders lost his life in defense of this community today. This was an unprovoked attack,” said Prince George’s County Police Chief Henry P. Stawinski.

It is not known what motivated the attack.

Prince George’s County Executive Rushern Baker said it was a “very sad day for Prince George’s County.”

Sunday night, Maryland Gov. Larry Hogan issued a statement reading, in part, “It is my hope that his (Colson’s) proud legacy of commitment and passion for law enforcement and serving others will provide some comfort in the difficult days that lie ahead.”

I am shocked & saddened by the news of the death of Prince George’s County police officer Jacai Colson. @PGPDNews pic.twitter.com/VraKDjko7U — Larry Hogan (@LarryHogan) March 14, 2016

See a map of the area of the shooting below:

The Associated Press, WTOP’s Dick Uliano and Ginger Whitaker contributed to this report