A 16-year-old Northwest Washington youth was killed and two other boys were injured in three shootings within a four-hour period in the District, authorities said yesterday.

A man was also killed in one of the shootings.

The youths were the latest casualties in a continuing surge of juvenile violence in the city. Sixteen juveniles have been slain in the District this year, four more than the number killed in all of 2003.

The teenage homicide victim was identified as David McMorris of the 800 block of Randolph Street NW. He was part of a group gathered at 9:30 p.m. Wednesday in the 3700 block of Georgia Avenue NW, near the Georgia Avenue-Petworth Metro station. Two gunmen approached the group and opened fire without saying a word, police said.

Three others -- two 26-year-olds and a 32-year-old -- were wounded, police said. They said that McMorris, a cousin of one of the wounded men, did not appear to be a target.

After the shooting, the gunmen jumped into a blue van and drove away, police said. Police voiced frustration yesterday that they had developed few solid leads even though as many as 40 people were nearby when the shooting occurred. Several were commuters emerging from the busy Metro station just a block away.

"We're hoping to get some more cooperation from the community," said Lt. Lamar Green of the violent crimes unit.

The shooting might be in retaliation for violence between feuding gangs in the area, Cmdr. Hilton Burton of the 4th District said, possibly stemming from a nearby shooting in May in which a 12-year-old girl was wounded by a stray bullet at Shepherd Street and Illinois Avenue NW.

"It appears this might be some dispute going back for a while," Burton said, adding that he is increasing patrols in the area.

Police officials and city leaders say they are distressed by the spike in the slayings of juveniles this year. Overall, homicides are down this year, and the District remains on track to record the fewest number of annual killings in nearly two decades. Through yesterday, 107 people have been slain on D.C. streets, police statistics show.

Just three hours after the Georgia Avenue incident, police responded to a shooting in Southeast Washington that left a man dead and a 16-year-old critically wounded. The man, whose identity was not released yesterday, was found shot in the head in the 3400 block of 25th Street SE, police said.

The 16-year-old was found around the corner. He was hospitalized in critical condition yesterday with a gunshot wound. Police did not release his name because he is considered a witness.

The third overnight shooting occurred at 1:30 a.m. in the 300 block of 50th Street NE. Police said a 10-year-old boy was wounded by shotgun pellets that pierced a wall in his apartment as he rested on a living room couch.

The youth, identified by relatives as Thomas McRae, was hit in the shoulder and back and taken to Children's Hospital. Police officials and friends said the boy was in stable condition and would probably not need surgery.

A 14-year-old boy who also lives in the apartment was charged as a juvenile with assault with a deadly weapon.

A D.C. Superior Court judge released the 14-year-old yesterday into the custody of his mother, who said her son spends summers at his grandmother's apartment, where the shooting occurred. The boy must adhere to a 7 p.m. curfew, the judge ruled.

The mother said she had warned her son about the danger of guns. "He can't even play with [toy] guns," she said. "I don't even buy them guns for Christmas. Guns are dangerous. They hurt people."

Police said the gunfire came from a bedroom next to the living room. Yesterday morning, a poster of the World Trade Center covered a gaping hole in the wall.

Willie Mae Sinclair, 53, lives in the two-bedroom apartment with several family members and friends, including Thomas and the 14-year-old. Sinclair said she does not believe the youth intentionally fired the gun.

She blamed one of her grandsons, a 19-year-old who does not live with her, for bringing the weapon into the house. "I kept telling him not to bring those things around," Sinclair said. "I'm upset with him."

The 14-year-old probably found the gun hidden in the bedroom, Sinclair said. He "just touched it and it went off," Sinclair said. "I guess it was curiosity."

After hearing the gunfire, Sinclair raced into her living room to find Thomas on the couch with speckles of blood on his shoulder and back. The 14-year-old was pacing and had a bloody, broken nose, apparently from the gun recoiling into his face, Sinclair said.

The 19-year-old grabbed the shotgun and ran out of the apartment before police or paramedics arrived, Sinclair and police said.

Cmdr. Robin Hoey said police were seeking the 19-year-old for questioning.

"The sad part is that some [guy] brought a gun into a house where kids were," Hoey said. "That is a terrible situation. This could have been a lot worse."

Police are offering a reward of as much as $25,000 for information leading to the arrest and conviction of suspects in the killings. Police urge anyone with information to call them at 202-727-9099.

Staff researcher Bobbye Pratt contributed to this report.

About 50 officers were on the scene near the Georgia Avenue-Petworth Metro station after a shooting Wednesday that killed a 16-year-old.