(CNN) -- Law enforcement were engaged Thursday night in "an active, armed standoff" with two people inside a southeastern New Hampshire home where, hours earlier, one police officer was killed and four others wounded, the state's attorney general said.
Police in Greenland had gone to a home in that community around 6 p.m. Thursday as part of what Attorney General Michael Delaney called a "drug investigation."
An "armed subject" who was inside the residence "shot rounds" at the officers, according to Delaney.
After the shooting, authorities were in a standoff with the gunman.
"Presently, the armed subject and a female remain inside the home ... and we are working with federal, state and local law enforcement officers," said Delaney, who was the only person to speak to the press -- without taking questions -- during a press conference at 10 p.m. Thursday.
Law enforcement personnel from numerous New Hampshire communities were in and around the scene Thursday night, video from CNN affiliate WMUR showed. Several residents told the station that police had ordered them to stay inside their homes or, if they were not in the area, had prevented them from going toward the shooting scene.
Greenland is a southeastern New Hampshire town of about 3,500 people just south of Portsmouth. According to its website, the town's police department has ten members, one of them being Chief Michael Maloney.
Delaney did not identify the injured police officers by name, adding that authorities are still contacting their relatives. He said that he could not offer much more information due to what he called "a dynamic and active and ongoing investigation."