A gunman ambushed two NYPD officers as they sat in a patrol car in Brooklyn Saturday, fatally shooting both of them before he turned the gun on himself in a nearby subway station, authorities say.

The shooting happened shortly before 3 p.m. in Brooklyn's Bedford-Stuyvesant neighborhood. Police say the armed man walked up to the passenger side of the officers' marked car and fired four shots, striking the officers in the head. Officials say the two officers were eating lunch at the time and never had a chance to draw their weapons to defend themselves.

Both officers were rushed to Woodhull Hospital, but were pronounced dead. They have been identified as Officer Rafael Ramos, 40, and Officer Wenjian Liu.

After the shooting, the suspect, identified as 28-year-old Ismaaiyl Brinsley, fled on foot. Two Con Edison workers followed him in their truck, and waved down two other officers in the area, who pursued the suspect. Brinsley ran into the nearby Myrtle Avenue subway station and fatally shot himself in the head on the platform.

Investigators say Brinsley, who had a lengthy criminal record, was a fugitive wanted for shooting his ex-girlfriend in Baltimore early Saturday morning. She remains in critical condition. After that shooting, Brinsley apparently traveled by bus to New York.

Before the shootings in New York, investigators say Brinsley posted comments that were "very anti-police" on social media accounts, including one comment where he allegedly wrote, "I'm putting wings on pigs today," and said "They take 1 of ours, let's take 2 of theirs." Officials say he also used the hashtags #Shootthepolice, #RIPErivGardner [sic] and #RIPMikeBrown, references to two black men who died during run-ins with police.

A wanted poster was faxed from Baltimore to the NYPD about Brinsley, but NYPD Commissioner Bill Bratton said it came over at around the time the officers were being ambushed.

New York City Mayor Bill de Blasio said the officers were assassinated "execution-style." He offered his condolences to both officers' families at a press conference Saturday evening, where he wiped away tears as he discussed their deaths. "Our entire city was attacked by this heinous individual," de Blasio said.

Authorities say the two officers were from the 84th Precinct, and were in the area for anti-crime operations at housing projects.

Officer Ramos, a three-year veteran of the force, was married and had a 13-year-old son and another in college. Officer Liu, a seven-year veteran, married his wife about two months ago.

A sea of officers gathered at Woodhull Hospital Saturday night and raised their hands in a silent salute as the two officers' bodies were taken away in by ambulance.