Three individuals were confirmed dead, four were injured, and nine others are unaccounted for after a small boat capsized early on Monday in high surf conditions off the San Diego coast, California.

The incident occurred shortly after sunrise when a 12-foot (3.7-meter) vessel overturned approximately 35 miles (56 km) north of the Mexico border.

Authorities have since deployed vessels and helicopters from the U.S. Coast Guard to search for the missing persons while those injured were transported to local hospitals for medical care.

Witnesses at Torrey Pines State Beach reported seeing the boat capsize around 6:30 AM. Lt. Nick Backouris of the San Diego Sheriff's Department stated that a doctor hiking nearby alerted emergency services after observing attempts at performing CPR on individuals on the beach.

Chris Sappey, a petty officer with the U.S. Coast Guard, indicated that details surrounding the origins of the boat remain unclear, although it has been identified as a type known as a panga, typically utilized for fishing and associated with smuggling activities.

Sappey noted that the individuals aboard the vessel are believed to be migrants rather than tourists.

The marine conditions at the time included fairly light winds and slow-rolling waves reaching around 6 feet (1.8 meters) in height, while the water temperature was recorded at 63°F (17°C), as reported by meteorologist Sebastian Westerink from the National Weather Service in San Diego.

As the search operation progressed, a bulldozer was seen moving the panga further up the beach.

The capsized wooden dinghy measured over 20 feet (6 meters) in length and exhibited scuffed blue paint, wooden planks used as seating, and was filled with various items, including a pair of running shoes, more than a dozen life vests, an empty waterproof cellphone bag, and several water bottles.

The vessel's single engine was also reported as visibly damaged.

Maritime smuggling along the California coast has historically presented a perilous alternative for migrants attempting to circumvent highly monitored land routes.

Small boats, often equipped with single or twin engines referred to as “pangás”, embark from the Mexican shoreline during the night, sometimes navigating hundreds of miles northward toward the U.S.

In a related incident this year, eight migrants lost their lives when two smuggling boats neared a San Diego beach amidst heavy fog, resulting in one of those vessels capsizing and marking one of the deadliest maritime smuggling incidents in U.S. waters.