(CNN)At least three people were missing and 13 others sent to hospitals Friday after apparently being dumped from a boat off the coast of San Diego, authorities say.
The rescued group was being smuggled into the US from Mexico, according to the US Customs and Border Patrol.
Emergency crews responded to calls of people yelling in the water early Friday morning, Encinitas Fire Chief Mike Stein said.
Three people were pulled from the ocean and another 10 reached the shore on their own, according to Stein. The 13 people were taken to local hospitals for treatment of mild hypothermia, deputy fire chief Robert Ford said.
The survvors included a 15-year-old girl, 13- and 15-year-old boys, two women and eight men, CBP reported.
Divers were searching for three who were still unaccounted for, authorities said.
"Reports from members of the group indicate there may have been as many as 18 people, including two smugglers, on board the vessel," CBP's release said.
"This is a 'dump and run' where the panga doesn't actually make it to shore," Stein said. "The boat drops people off to swim, then returns to Mexico."
A panga is a boat often used for working off the coast of Mexico or Central America, according to the US Coast Guard. The engine-powered vessels are typically 25 to 45 feet long.
Authorities were searching for the boat and two operators, according to US Border Patrol Agent Kurtis Kantura.
Kantura said panga boats are dangerous because they lack communication devices.
"They care little for human life and will do anything they can to make a dollar," he said of the boat operators.