A 12-year-old girl wounded by a stray bullet Sunday night while sitting on her front porch in the Petworth neighborhood of Northwest Washington was probably caught in a feud between rival drug groups, D.C. police said yesterday.

As officers canvassed the neighborhood in hopes of gathering clues, police offered a reward of up to $11,000 for information and appealed for the public's help in solving the latest in a series of shootings of bystanders.

Three weeks ago, 8-year-old Chelsea Cromartie was killed by a stray bullet as she watched television in a Northeast Washington house. In April, a 45-year-old woman was wounded as she tried to shield a young child from gunfire on her Northwest Washington street.

Police declined yesterday to identify the girl shot Sunday, saying she is a witness in the case. She was in stable condition yesterday at Children's Hospital after being treated for a gunshot wound to the abdomen, police said.

The girl was sitting on the porch of her home about 8:50 p.m. when one of two men on a red motorized dirt bike or motorcycle opened fire at a car, police said. There were conflicting reports yesterday as to whether someone in the car returned gunfire.

One bullet hit the girl. The men drove away, leaving behind about a dozen shell casings, police said.

Police said they strongly suspect that two warring drug factions were responsible for the shooting -- as well as another burst of gunfire hours earlier in the 600 block of Quincy Street, a few blocks away.

That shooting, which occurred about 6 p.m., left a 17-year-old boy with a minor gunshot wound to his left ankle, said Cmdr. Hilton Burton of the 4th District.

Police identified one group as operating near Taylor and Eighth streets and Georgia Avenue NW and the other on Warder Street and Rock Creek Church Road NW. The two groups sell mostly marijuana and cocaine, police said.

The area of Sunday's shooting was described by police officials as straddling the turf of both groups. The disputes are often personal in nature and not always related to drugs, according to police officials, who added that the investigation is in its preliminary stages. They said they are investigating other potential motives behind the attack but declined to discuss them.

The two feuding groups were tied in court documents to an earlier killing in the same block where the 12-year-old girl was hit. On Jan. 19, a 17-year-old was killed and two friends were wounded as they drove along Shepherd Street, police said.

Police said in court documents charging an accomplice in the killing that the two groups had a "long-standing feud," with the victims belonging to one group and the suspect to the other.

Shortly after that killing, the area of Shepherd Street NW between Fourth Street and Georgia Avenue was named one of the city's 14 "hot spot" areas that merit stepped-up attention from police and other city agencies. Despite the designation, some residents and D.C. Council member Adrian M. Fenty (D-Ward 4) said that police were not doing enough. "It's like it's all promises without any follow-through," said Fenty, who represents the area. "There has been virtually no increase in police presence."

Burton and other commanders defended the police department's response. "We're doing the best we can," Burton said. "We respond. . . . When random shootings like this occur, we ratchet up the activity in the area."

Last night, members of the area Orange Hat Patrol and neighbors -- about 50 people in all -- marched along several blocks of the community with D.C. Police Chief Charles H. Ramsey, Burton and Fenty to show solidarity in the fight against crime.

At the site of Sunday night's shooting, the group stopped to hear speeches from people including Minnie Green, leader of the area Orange Hat Patrol, who complained about a lack of police presence in the neighborhood and urged residents to take "back our community."

News researcher Bobbye Pratt and staff reporter Allan Lengel contributed to this report.

Longtime resident and Orange Hat Patrol leader Minnie Green fills in D.C. Police Chief Charles H. Ramsay on the troubles of the neighborhood at the site where a 12-year-old was wounded. A group of residents marched several blocks through the community to the scene. Green urged them to take "back our community."