SAN DIEGO (AP) — Authorities say a horse trailer carrying about 18 people who entered the country illegally overturned on a Southern California highway just north of the border with Mexico.

The San Diego Union-Tribune says several people inside the trailer were hurt in the crash Saturday near Campo, with injuries described as moderate and minor. Six patients were hospitalized.

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The California Highway Patrol says a witness reported that the two-axle trailer being hauled by a pickup truck began to fishtail and eventually tipped onto its right side along northbound Interstate 8.

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The newspaper says authorities rounded up most, if not all, of the people involved. The CHP reported 18 individuals, while Border Patrol said there were 19. The reason for the discrepancy was unclear.

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Officials say the pickup driver was not immediately identified.