A teenager was stabbed and seriously wounded in a fight Monday at the National Zoo as the zoo marked African American Family Day. A 16-year-old was arrested and charged in the incident, D.C. police said.

D.C. police Cmdr. Michael E. Reese said the stabbing was connected to “some kind of ruckus” that apparently broke out within the zoo and might have resumed at or near the entrance on Connecticut Avenue NW.

The victim was in stable condition Monday night, police said. No age was given for him, and he was not identified. The family-day celebration is a tradition at the zoo on the day after Easter.

The motive in the attack remained unclear Monday night.

Police spokeswoman Gwendolyn Crump said the suspect, from Southeast Washington, was charged with assault with intent to kill. He was not named. It wasn’t clear whether police were looking for additional suspects.

Reese, who is head of the 2nd Police District, said the fight might have stemmed from an ongoing dispute. Or, he said, it might have been over “something that just happened right there.”

The teenager was stabbed at least twice, at least once in the zoo and once at or just outside the entrance, Reese said. Some of the same assailants might have been involved in both attacks, he said.

A zoo spokeswoman said the victim left the zoo on his own. He was later found by police on Connecticut Avenue near the zoo entrance and was taken to a hospital.

Pete Piringer, a D.C. fire department spokesman, said the victim was found bleeding shortly after 4 p.m. outside an apartment building in the 2900 block of Connecticut Avenue NW. He described the wounds as possibly life-threatening.

The fight broke out about 3:30 p.m. near the Small Mammal House, authorities said. Zoo spokeswoman Jodi Legge said zoo security ejected an unspecified number of people, many of them juveniles, as a result of the fight.

Legge said the zoo, with a capacity of 25,000 visitors, was “extremely crowded” Monday.

In addition to the many children attending the zoo’s annual day-after-Easter celebration, tourists and youngsters on spring break filled the zoo to capacity, Legge said.

The free gathering dates to the 1890s. Oral history says that black domestic workers were required to work on Easter, so Monday was the day of family celebration.

In 2000, the Easter Monday celebration was marred when a teenager, in a dispute with teens from another neighborhood, shot and wounded seven people at the zoo’s main entrance. A year later, the shooter was sentenced to 25 years in prison.

Staff writers Pat Sullivan and Clarence Williams contributed to this report.