A screengrab from NBC's web stream shows the traffic collision site near the U.S.-Mexico border in U.S. Southern California, where over a dozen people were killed on March 2, 2021.(Photo: Xinhua)

All 13 people killed when a packed vehicle collided with a truck in California are believed to have entered the US illegally through a nearby breach in the Mexico border fence, US authorities said Wednesday.

A 10-foot gap in the frontier barrier was found around an hour before officials learned of Tuesday morning's deadly crash, which took place around 30 miles from the border rift.

Initial investigations "indicate a potential nexus to the aforementioned breach in the border wall," said El Centro Sector Chief Patrol Agent Gregory Bovino in a statement.

Surveillance footage showed two vehicles collecting border crossers from the site of the breach early Tuesday.

As well as the fatal crash, a second car was found broken down and in flames by border patrol agents, who located another 19 individuals hiding in the brush nearby who had entered the US through the fence.

Neither car was being pursued by law enforcement when the incident occurred, the US Customs and Border Protection statement said.

Tuesday's accident occurred when an SUV carrying more than two dozen people - including minors - and a semi-truck crashed near El Centro, California.

At least 10 of the deceased victims were Mexican, according to the Mexican government.

A total of 25 occupants - including a driver who was later among the dead - were traveling in the SUV at the time of the crash, the statement said.

The Ford Expedition SUV would have a legal capacity of about eight people, according to the carmaker's website. 

AFP