Firecrackers thrown at an annual winter festival at the National Zoo, followed by the shootings of two teens on the street outside, have renewed concerns about safety at the Woodley Park attraction.

Security was increased after the Saturday incidents, and zoo officials said guards will conduct bag checks and use handheld metal detectors on some days at ZooLights, a display that runs through New Year’s Day and attracts thousands of visitors.

In addition to the shootings and the firecrackers, police said youths on Saturday night entered FroZenYo yogurt shop, across Connecticut Avenue from the zoo’s main entrance, and may have assaulted an employee and taken items. Workers at two other businesses, open late to capitalize on the crowds, locked their doors to escape the frenzy.

“I’m just frustrated because at this point I would just like to see a system put into place at the zoo where the visitors they attract every year are protected,” said Lee Brian Reba, an advisory neighborhood commissioner in Woodley Park.

Reba said the incidents “disturbed the community, disrupted an event, caused panic and shut down the main thoroughfare between Maryland and the District.”

Authorities on Monday provided a more thorough account of how the mayhem unfolded Saturday night, starting with firecrackers that many people mistook as gunfire. Authorities said that was followed by an assault by a juvenile on a patron and a large crowd of young men and women at the entrance that prompted zoo officials to close the festival an hour early.

As young people spilled onto Connecticut Avenue, police said someone shot a 15-year-old and a 16-year-old about three blocks south of the zoo entrance. The older youth was struck several times. The younger boy was shot once and found about 30 minutes later about a half-mile away on Calvert Street. The injuries to both were described as not life threatening.

Police Chief Peter Newsham said detectives do not have a good description of a suspect in the shootings and no arrests have been made. He said police believe the wounded youths had been at the festival but do not know if the shooting was connected to anything that happened inside.

“I think more than likely the zoo had an early closure of their event and kids that left got into some kind of confrontation when they made their way to the 2800 block of Connecticut Avenue,” Newsham said.

The zoo last year nixed ideas for screening centers near entrances amid concerns from residents that the measures would close off the open campus. The zoo is in the process of extending a perimeter fence and reducing the number of entrances from 13 to six, to make it easier to monitor visitors.

Pamela Baker-Masson, a spokeswoman for the zoo, said that the firecrackers set off around 7 p.m. created a “very chaotic and scary” moment and that police were unable to find the culprits.

She said the event was closed around 8 p.m. following an assault, where a patron was struck, and crowds at the entrance. Baker-Masson said zoo police were at that time escorting unruly teenagers out of the park. She said that the zoo had “staffed appropriately for a big crowd” and that this was the first problem in the event’s 13-year run.

Yael Krigman, who owns Baked by Yael bakery on Connecticut Avenue, said her staff quickly locked their doors as a disruptive crowd of youths descended on the yogurt shop next door.

“We were fortunate,” said Krigman, whose bakery became the spot for a meeting on Monday with police, zoo officials and District leaders. She said the zoo should quickly notify businesses when there are disruptions so staff can prepare.

But Krigman said ZooLights is crucial for business. The zoo estimated 20,000 people visited Saturday night, and the bakery welcomed customers seeking cake or its signature “hot chocolate on a spoon.”

“We get more foot traffic during ZooLights than at any other time during the year,” Krigman said.

Fenit Nirappil and Clarence Williams contributed to this report.