Two members of the British military conducting skydiving training in southern California collided in mid-air on Friday and were hospitalized with serious injuries, authorities said.

It was not immediately clear if the two men's parachutes opened before they hit the ground in Lake Elsinore, about 60 miles southeast of Los Angeles, said Cheri Patterson, a spokeswoman for the Riverside County Fire Department.

One of the skydivers was in cardiac arrest when he was taken to the hospital after the mid-air collision and the other was in critical condition, Patterson said.

Both were members of the British military training at the Skydive Elsinore facility, said Riverside County Sheriff-Coroner spokeswoman Corporal Courtney Donowho.

Authorities did not release the identities of the skydivers, but Patterson said both men were in their 20s.

A spokeswoman for the British Consulate in Los Angeles could not be reached for comment.

The British military is investigating the mid-air collision and interviewing witnesses, Donowho said.