Update 12:13 p.m. ET:

CNN reports that the Conception sunk 20 yards offshore as emergency responders worked to fight the blaze.

Update 10:28 a.m. ET: CNN reports that the vessel is a diving boat called the "Conception." The boat reportedly left on an excursion on Saturday, and was due to return to port on Monday. Bill Nash of Ventura County PIO said, "It's a large boat, and we know we have numerous fatalities. I don't have an exact number."

Update 10:14 a.m. ET: Reuters is also reporting that there have been several deaths in connection with the boating incident, but the Coast Guard has not confirmed details.

"We cannot speak to whether there were fatalities," Coast Guard Petty Officer Aiden Cooney told the news organization by phone, pointing out that five people had been rescued.

"The situation is still ongoing," he continued, pointing out that there was no information available on 29 people who have not yet been rescued. "The last information we have is that they're still on board."

Original story below

The U.S. Coast Guard is assisting in a rescue on Monday morning after a boat incident involving at least 34 people on board off the coast of Ventura County, California.

What do we know about this so far?

Ventura County officials told KTLA-TV that 34 people are dead so far, but a rescue is still underway.

The U.S. Coast Guard did not confirm any fatalities, but said that the incident took place near Santa Cruz island.

The Coast Guard Los Angeles confirmed they have rescued five, CNN reported.

"All we can say is the boat is on fire," the Coast Guard tells CNN.

In a tweet, the U.S. Coast Guard said that "A group of crew members has been rescued (one with minor injuries) and efforts continue to evacuate the remaining passengers." A 75-foot vessel was said to be on fire, according to the Coast Guard.

A previous tweet explained that the Coast Guard "launched multiple rescue assets along with assets from local agencies to assist more than 30 people in distress on a 75ft boat near Santa Cruz Island."

This is a developing story and will be updated as events warrant.