UPDATE: 11:13 AMThe missing hikers have been located safely. No serious injuries were reported. This post has been updated throughout.
Rescue personnel are searching for up to 15 hikers who did not return from a hike near Eaton Canyon in southern California on Sunday.
ABC News reports that two helicopters have joined the search for the church group, which is reportedly comprised of experienced hikers ranging from 14 to 36 years old. The group phoned in a distress call late Sunday night.
Eaton Canyon is located near the southern edge of the San Gabriel Mountains, roughly 16 miles northeast of Los Angeles. Heavy fog hindered overnight search efforts, local news affiliate KTLA reports, but the weather was expected to clear on Monday morning.
The group was said to be carrying canyoneering equipment including ropes, harnesses, and helmets, but did not have overnight gear.