The first murder, which police were notified of at 5:47 p.m., claimed the life of a 21-year-old man in Brownsville, Brooklyn, cops said.

The victim was found with a gunshot wound outside a building on Christopher Avenue near Pitkin Avenue. He was taken to a Brookdale University Hospital Medical Center and pronounced dead, police said.

Three minutes later, police received another call of a person shot in the Claremont section of The Bronx.

There, a 29-year-old man was later discovered by emergency responders with a gunshot wound to the chest.

The victim was taken to a nearby hospital, where he was declared dead.

At about 6:45 p.m. in Harlem, a 15-year-old boy was shot outside a building on Madison Avenue near East 111th street, cops said. He was taken to an area hospital and is expected to survive.

Just after 8 p.m., three men were shot inside 306 East 171st Street in The Bronx — two blocks away from the earlier fatal shooting.

A 22-year-old man who was shot to the chest, and a 27-year-old man who took a bullet to the neck were pronounced dead at St. Barnabas Hospital, police said.

The other victim, a 29-year-old, was shot in the arm. He was taken to Lincoln Hospital in stable condition.

On Staten Island at about 8:47 p.m., police found a 45-year-old man shot to the head in a building on Gordon Street in Stapleton, according to police.

The shootings extended a violent weekend in The Big Apple, where 39 people were shot, three fatally, between midnight Saturday and 6:30 a.m. Sunday, sources said.