The Mexican navy says it has detected a disturbing trend of migrant smugglers abandoning boatloads of people at sea off the coast of Baja California.

The Navy says that each month it has been finding an average of 10 to 12 boats, with a total of about out 150 migrants. It doesn't say when the discoveries began.

The Navy said Monday the boats' captains abandoned the vessels aboard other craft, telling migrants the motors had broken down and they would be back.

The smugglers then left the migrants adrift, often in overcrowded boats without food or radios, putting their lives at risk.

A video released by the navy shows sailors approaching several vessels, some in choppy waters, to rescue ragged-looking passengers.