COLUMBIA, S.C. — More than 20 people were arrested and more than 300 dogs were recued as authorities raided dogfighting kennels in South Carolina, federal prosecutors said Monday.

The sting started when state and federal agents interrupted a dog fight in Richland County on Saturday, U.S. Attorney Adair Boroughs said in a statement.

That led agents to serve 23 warrants on Sunday that were known to be places were dogs fight or are trained to fight in Clarendon, Lee, Orangeburg, Richland, Sumter and York counties, investigators said.

Twenty people face state charges of animal cruelty and dogfighting, authorities said. Investigators also seized about 30 guns and $40,000 in cash, prosecutors said.

Officials said 305 dogs were rescued, with about 275 of them believed to be part of the dogfighting ring. The Humane Society of the United States and Bark Nation is helping take care of the dogs.

Some of the dogs had severe scars, open wounds and cuts, the Humane Society said.

Some of the dogs were unusually thin, chained to trees with no way of getting food or water, the agency said.

The arrests over the weekend are the first steps in a broader investigation that could include federal charges, Boroughs said.

“To force dogs to fight, often to the death, for the enjoyment of others is not only a federal crime, it is also cruel, sadistic, and can create a haven for other illicit activities involving drugs and firearms,” Boroughs said.