BALTIMORE –– Baltimore police said an off-duty officer shot a man who pulled a gun on the officer during an apparent home invasion attempt.

Police spokesman Anthony Guglielmi said the man was shot at least five times and taken to Hopkins Bayview Hospital in critical condition.

Guglielmi said the officer was not in uniform at the time of the incident. He said the officer was at the door of his northeast Baltimore home at about 1 p.m. Monday when the man approached and put a gun to the officer's back.

The officer told police he went inside and was told to lay on the floor. At that point, the officer drew his service weapon and identified himself.

Guglielmi said a chase ensued and the man, who is not being identified, was shot about three blocks away.

"We heard four shots," said resident Gary Galloway, who was watching TV at the time, heard gunshots and saw a man running with another armed man in pursuit. "(The officer) was just walking and firing. He never said a word. He was on a cell phone."

Resident Kerri Williams said her house was hit.

"I was really terrified because my 4-month-old baby was in the house," she said.

Police said they recovered a gun from the suspect but weren't sure if he had fired it.

"At one point, he put his hands up and his hands were empty," Galloway said, who heard the suspect say something. "He said, 'I'm sorry man.' Like he was apologizing for whatever he did."

Police said the man, who has not been identified, has a lengthy arrest record.

Officers escorted students from a nearby school home Monday afternoon as a precaution. A three-block area was sealed off to search for evidence.

Authorities said they found shell cases that don't appear to belong to the officer's gun, which would suggest someone else was firing a gun.

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