Despite strong opposition from environmentalists and others, the federal Environmental Protection Agency announced this past week that it had reauthorized the use of spring-loaded poison devices known as “cyanide bombs” to kill coyotes, foxes and other animals that prey on livestock.

The devices, officially called M-44s, have been used continuously for more than four decades by Wildlife Services, a program within the United States Department of Agriculture. When a predator stumbles across one of these devices, a capsule containing sodium cyanide, a highly toxic pesticide, is ejected into its mouth.

In August 2017, the WildEarth Guardians and the Center for Biological Diversity filed a lawsuit that asked the E.P.A. to ban the use of sodium cyanide, generating a review of the program. On Tuesday, the agency announced it would continue using M-44s on an interim basis but would toughen restrictions based on its review.

Last year, the devices killed more than 6,500 animals across the country, according to the Department of Agriculture. More than 200 of the animals killed — including foxes, raccoons, opossums, skunks, swine and a black bear — were unintentional targets of the cyanide bombs, according to the department.