About 300 endangered sea turtles were found dead off the southern coast of Mexico on Tuesday, trapped in fishing nets, shortly after more than 100 dead turtles were recovered.

Fishermen in the southern state of Oaxaca discovered the turtles in the seaside community of Barra de Colotepec, said Heliodoro Diaz, the coordinator of the state's civil protection agency.

Images captured by a Reuters videographer showed dozens of dead turtles, many beginning to decompose, caught in what appeared to be a net.

The olive ridley turtles, which Mexican authorities say are at risk of extinction, measure about 75 centimeters (29.5 inches) in length and weigh some 45 kilograms (99 pounds).

From May to September, they descend on various Mexican states along the Pacific Ocean to lay their eggs.