ROME — Hundreds of crop pickers held a one-day strike and protest march in southeastern Italy Wednesday to protest the exploitation of migrant farmworkers.

Labor union activists organized the strike and march from the shanty town of San Severo to the city of Foggia after 16 farmworkers died in two recent road accidents in the Foggia area.

Flanked by labor leaders, the protesters held signs reading "Never Slaves" and "We are workers, not meat for the butcher." Many waved flags of the left-wing USB labor union.

Workers said there was running water or electricity in the shanty town. Activists said crop pickers are charged for rides in overcrowded, rundown vans to the fields and orchards where they spend long hours laboring in the sun.

The farmworkers who were killed on Saturday and Monday were riding in vans that collided with trucks carrying tomatoes. Prosecutors are investigating to determine if the vans safe.

Most of the crop pickers who work in Italy's verdant Puglia region are foreigners, typically from Africa or eastern Europe. Union leaders and the farmworkers themselves contend they often are paid below union wages.

Italy's previous center-left government successfully lobbied in 2016 for a law intended to prevent the exploitation of agriculture workers, both migrants and Italians. It authorized stiffer penalties for labor recruiters and employers.

Italian Premier Giuseppe Conte, who heads Italy's new populist government, told reporters Wednesday that enforcement of the law must be improved.