After a raucous birthday party at Kudeta spilled out onto Temple St. on Sunday night, the New Haven Police Department opened an investigation into whether the restaurant complied with city regulations of underage parties.

On Sunday evening, a birthday party held at the Asian fusion restaurant grew so out of control that dozens of NHPD officers had to be called in to control the chaos. Police initially responded to calls of fighting on Temple St., but arrived at the scene to find that hundreds of teenagers from the party had streamed out of Kudeta, causing general mischief on the street. Department spokesman David Hartman said that NHPD officers dealt with teenagers who were harassing pedestrians and drivers as well as fighting one another.

“When [the first NHPD officers] got there, they realized that it was more than they could handle, so they called in for backup,” said Chris Candido, co-owner of neighboring Temple Grill. “That’s when quite a few came down and had to handle the situation.”

May Lin, the manager at Kudeta, could not be reached for comment.

The birthday party, entitled “The All Black Affair Party at Kudeta,” was held in celebration of a local teen’s 16th birthday. Invitations to the affair revealed a $10 price of admission for those who came to the party with a certain flyer, while those without one had to pay $15 to gain access to the restaurant. A story published on Monday by the New Haven Independent reported that the mother of the boy for whom the party was thrown collected these fees at the door.

At 7 p.m., Kudeta’s doors opened to guests of the party, but by 9 p.m., fights had already broken out on Temple St. Hartman said that officers at the scene were focused on controlling the crowd, since no assaults or injuries were reported. The NHPD made no arrests at the incident.

After the events of Sunday night had died down, however, NHPD officials began looking into the legitimacy of Kudeta’s arrangement to host a party for underage guests. Events held primarily for under-age patrons in locations that normally serve alcohol are called “juice bar” events and must comply with certain standards set forth by city and state law.

“As used in this section, ‘juice bar or similar facility’ means a café, or an area within a café, in which nonalcoholic beverages are served to minors,” reads the City Ordinance on Juice Bar events.

The Ordinance describes the criteria an establishment must meet before it can be recognized by the NHPD as valid. These criteria include: providing written notification of the event’s details to the NHPD at least 48 hours in advance, hosting a designated police officer during the event and isolating all alcohol from the areas in which minors are expected to be.

Hartman said that, though he does not suspect illegal alcohol sales played a role in the ensuing chaos, the NHPD is investigating how thoroughly Kudeta abided by the Ordinance’s other conditions. Hartman also said the NHPD was not aware that the event was taking place; otherwise, an officer would have been on hand to monitor the party, per the Ordinance’s policy.

Juice Bar events are fairly prevalent throughout New Haven, Candido said, though he said that Temple Grill does not host them. Some guests from the Kudeta party made their way to Juice Bar events at nearby establishments like Mynt Night Club and The G.O.A.T. Bar — both of which appeared to meet the Ordinance’s standards, Hartman said.

“A Juice Bar allows people that are not 21 to go out to a restaurant or club atmosphere and dance, party and listen to music,” Candido said. “They are very popular: Those people are old enough to go out and they enjoy the atmosphere of socializing.”

Kudeta is open from 11:30 a.m. to 10 p.m. every day.