NEW YORK, May 29 (Xinhua) -- An off-duty rookie police officer was killed by a fellow cop Thursday night in a shooting in East Harlem of New York City in what appears to be a case of mistaken identity.

    Police said the 25-year-old officer, Omar Edwards, married and father of two small children, was confronting suspect Miguel Santiago, who has five prior arrests for drugs, assault and robbery.

    When Edwards was approaching his car at about 10:30 p.m. local time, he saw Santiago breaking into his car. Edwards called 911, drew his gun and started chasing Santiago.

    Plainclothes officers responded to the scene and fired six rounds at Edwards, hitting him in the arm and chest. He was not wearing a bullet proof vest at the time.

    Edwards was rushed to hospital, and was pronounced dead about an hour later.

    "This is a tragedy. Rest assured we will find out exactly what happened here, see what we can learn from it so it may never happen again," local TV channel NY1 quoted New York Mayor Michael Bloomberg as saying.

    "On behalf of the entire department, I extend our deepest condolences to the family and friends of Officer Edwards," New York Police Commissioner Ray Kelly was cited as saying.

    Harlem is a neighborhood in the New York City borough of Manhattan, long known as a major African-American residential, cultural, and business center. As a neighborhood with a long history of marginalization and economic deprivation, Harlem has long been associated with crimes.