A small boat is believed to have carried the immigrants near the San Diego coast, with at least three people dead and four others injured. The U.S. Coast Guard said earlier Tuesday that crew members had suspended at least seven missing persons.

U.S. Coast Guard officials told CBS News that the Panga-style boat — a small, open outboard-powered fishing boat — topped off near Torrey Pines State Beach, with at least 16 people on board. There were at least two children, according to San Diego CBS affiliate KFMB, which also reported four people were hospitalized after the incident.

The Mexican Consulate General confirmed in Santiago on Tuesday that two dead and two hospitalized people have been Mexican nationals.

Coast Guard officials told CBS News it regards it as a suspected human smuggling incident.

Chris Sappey, a young U.S. Coast Guard officer, told the Associated Press that it is not clear where the ship came from about 35 miles north of the Mexican border. He said similar ships are often used by smugglers.

"They are not tourists," Sape said. "They are believed to be immigrants."

Officials had no other details about the people on board, including the three who died. It is not clear if anyone will go to shore and leave the area by themselves, the Associated Press reported.

The San Diego County Sheriff’s Office said its representatives were assisting.

The sheriff told KFC that no one was detained for the incident.

Video released by the station shows empty boats near the coastline of Tory Pines State Beach, lifeguards patrolled water and law enforcement vehicles parked on the beach. Coast Guard helicopters investigated the area from above.

Witnesses reported seeing a boat tilted near the coast at around 6:30 a.m. local time, Lieutenant Nick Kidris of the San Diego Sheriff’s Department told the Associated Press.

Backouris said: "A doctor nearby called and said, 'I saw people doing CPR on the beach and I was running.'

The wooden boat is 20 feet long and is padded through blue paint and board seats, according to the Associated Press. There is a pair of running shoes, a dozen life vests, an empty waterproof mobile phone bag and various water bottles in the boat.

In addition to sheriff's representatives and the Coast Guard, Encinitas Fire Department and U.S. Customs and Border Patrol officials were also on the scene, according to KFMB.

Deputy Fire Chief Jorge Sanchez said in an interview on site that the immigration status of the personnel on board was "not yet known". Sanchez said several people were found on the beach after the ship flipped and confirmed that it was considered a "massive casualties."