“I hope he’s going to be O.K.,” Councilman Eugene said.

Officers responded to three 911 calls on Saturday night reporting gunfire in the East Flatbush neighborhood, where several people were attending a party, the police said. The officers concluded that the reports had probably been in response to fireworks.

On Sunday, police tape cordoned off the sprawling crime scene in the area, blocking rows of homes with neatly trimmed bushes and blossoming rose gardens.

At a home on Tilden Avenue near East 53rd Street, there were remnants of a birthday party for a 2-year-old boy, according to the boy’s grandmother, who declined to provide her name because she feared retaliation. The decorations included a colorful arch of balloons.

The party started late, postponed by the threat of rain, the grandmother said. It ended around 11 p.m., but the boy’s parents and other young adults lingered on the porch, leaving red cups on the railing that remained on Sunday afternoon.

The boy’s grandmother said she did not know whether any fireworks had been set off. But she said the police had come to the party and asked the guests not to use them. A group of teenagers had been hanging out across the street before the officer was hurt, she said.

Monique Dixon said she was returning from dinner on Saturday and had been waiting for a parking spot on Snyder Avenue nearby when she heard two gunshots.