A fourth dog has died after eating poisoned meatballs littered around a cross-country race in France. Authorities believe the person responsible wore gloves to hide fingerprints.

• Four dogs have now died due to poisoned meatballs sprinkled around a cross-country trail in France.

• Three dogs died within a span of 15 minutes after eating the meatballs last Sunday, per The Times.

• On Tuesday, a fourth dog ate them on the trail and later died, according to France 3.

A string of poisonings has rocked the southern French town of Vauvert after three dogs were poisoned at a cross-country race last Sunday, and two other dogs were poisoned days later.

According to the New York Times, as dog owners and their pets arrived at the scene of a cani-cross race — a cross-country race where runners or cyclists are attached to their dogs — tragedy struck in the early morning. As the dogs and their owners prepared for the race, three dogs started convulsing and vomiting and died within 15 minutes.

Over 50 poisoned meatballs were littered around the race site, almost instantly killing the dogs, according to the report. The site was closed off and the annual race was immediately canceled.