A homeless man was critically injured Friday after being set on fire outside a New York City church where he had bedded down for the night.

Police were searching for three teenage boys in what homeless advocates say was one of the most severe and senseless attacks on a homeless victim in recent memory.

"I haven't heard of an incident like this in many years in New York," said Mary Brosnahan, executive director of the Coalition for the Homeless.

While the severity of the attack was unusual for New York, other U.S. cities have seen recent spates of violence aimed at homeless people.

The torching of Felix Najera, 49, bewildered and stunned residents around Bethany Christian Church in upper Manhattan's East Harlem neighborhood. The 49-year-old victim was a heavy drinker who would ask passers-by for cigarettes, but otherwise was considered a harmless figure.

"It's a shame," said Gary Williams. "He doesn't bother anybody."