Update: The Department of Public Health said on Monday that the candy was likely edible marijuana.

Nineteen people were sent to the hospital after eating an unknown substance during a quinceañera Saturday night in the Mission District, according to the San Francisco Fire Department. Three children, including a 9-year-old, are in critical condition.

Firefighters were called to the Women’s Building at 3543 18th St. between Valencia and Guerrero streets just before 10:30 p.m., according to the department’s spokesperson. First responders initially treated six people at the party, but that grew to 17 during the night, the spokesperson said. Two other adults transported themselves to the hospital later.

The victims described eating the same type of gummy candy at the party, which the spokesperson said looked to be attended by over 100 people.

“All victims ate a candy that is described as a gummy ring type of a candy,” said Jonathan Baxter, the spokesperson with the Fire Department. The youngest victim was a 6-year-old child, but over half the victims were less than 18 years old. Three children were admitted to the intensive care unit, Baxter said, but all shared common symptoms.

“The signs and symptoms associated with this are heart palpitations, shortness of breath, some with a rash, some with an additional swollen tongue,” Baxter said. The symptoms were in varying degrees of severity, Baxter said, with some having just a mild rash while “another person might not even be able to talk.” The 9-year-old in critical condition has a severe reaction, Baxter said.

The Fire Department is asking anyone who attended the party and ate the candy to call 911 for evaluation. The Police Department had a “very heavy presence” after the incident, Baxter said, and was working to determine more. The police asked anyone with more information to contact their anonymous tip line at 415-575-4444.

The Department of Public Health is working on determining the identity of the substance.

The department was asking people to avoid the area an hour after the first calls were made, and police officers and firefighters blocked 18th Street to vehicular and foot traffic. The street was cleared by midnight on Saturday.

This post was updated as the number of reported victims grew from eight initial victims to 17 later on Saturday night. The Fire Department then reported 19 victims total on Sunday.