(CNN) -- Two New York City police officers and five civilians were shot, one of them fatally, in an incident early Sunday morning in Manhattan, a police spokesman said.
At about 3 a.m. Sunday, officers responded to an argument at a block party in Harlem, Police Commissioner Raymond Kelly said at a news conference.
At the scene, a man police identified as Angel Alvarez and another man were arguing, apparently over a woman, Kelly said.
Alvarez shot and killed the other man, and then shot at officers as they approached, he said.
Police officer Michael Tedeschi was struck in the chest, which was protected by a bullet-resistant vest. A second officer, Alfredo Vargas, was grazed on the hand by a bullet, Kelly said. Two additional officers were injured when they fell down.
The four police officers returned fire, striking Alvarez several times, Kelly said. Alvarez was hospitalized in critical but stable condition.
A .38-caliber revolver was recovered at the scene, Kelly said.
Besides the two men arguing, three other civilians were shot in the incident and all were in stable condition.
"We're very lucky today," New York Mayor Michael Bloomberg told reporters. "Two police officers shot, fortunately not seriously. But there but for the grace of God, it could have been much worse. And in terms of our abilities to protect ourselves, to be safe on our streets, we've just got to do something about all these guns -- the guns that keep flooding into our cities."
The police officers fired more than 40 bullets, Kelly said. Other casings at the scene didn't match police weapons, he said.
CNN's Miguel Susana contributed to this report.