Los Angeles County Fire Department trucks respond to a call. LA County Fire Department photo

(AP) — Authorities in Southern California responded to a slow leak from a chemical tank on Tuesday but quickly got it under control.

The substance and the leak’s origin remain unknown, Los Angeles County Fire Department spokesperson Kaitlyn Aldana said.

Three people on scene declined transport to a hospital, she said.

Photos posted to social media showed what appeared to be an orange haze or mist in the sky.

La Habra Mayor Jose Medrano urged residents to shelter in place and said some streets were being evacuated.

Luis Gomez, who manages a pickleball program nearby, said he could see an orange cloud rising in the sky. He called police and was told anyone within a mile radius of the location is under an evacuation order.

“They said, ‘if you’re inside the one-mile (radius), you have to leave right now,'” Gomez said, adding he’s closing down his program for the rest of the day

The area is a mix of residential neighborhoods and industrial warehouses about 10 miles (16 kilometers) north of Anaheim.