ST. LOUIS - As many as 350 dogs were seized and about 30 people arrested yesterday during raids in five states that animal-welfare groups are calling the largest simultaneous raid of dogfighting operations in the U.S.

U.S. attorneys in four of the states announced related indictments accusing 26 people of cruelties ranging from denying animals medical treatment to shooting dogs in the head when they didn't fight well, then throwing their carcasses into a river or burning them in a barrel.

Task forces of federal, state and local law enforcement agencies conducted the raids and made arrests in Missouri, Illinois, Iowa, Texas and Oklahoma following a more than year-long investigation prompted by information gathered by the Humane Society of Missouri. It wasn't clear whether or to what extent the operations were related.

Kathy Warnick, president of the Humane Society of Missouri, said tips had come in from "multiple sources" about dogfighting, and anticruelty workers worked with federal authorities for 18 months.

"This heinous, heinous bloodsport is not going to be tolerated," she said.

The national Humane Society said there also were arrests in Arkansas associated with dogfighting, but no dogs were seized.

Dogfighting is banned throughout the United States and is a felony in 50 states. A law enacted two years ago increased penalties for activities that promote or encourage animal fighting after a long campaign by animal-welfare groups.

The Humane Society of Missouri is sheltering more than 300 dogs - believed to be mostly pit bull terriers - seized in Missouri and Illinois raids and their conditions are being assessed.

HSUS spokeswoman Jordan Crump, a spokesman with the Humane Society of the United States, said each dog seized in the raids will be evaluated by behaviorial experts in hopes of placing as many as possible in adoptive homes, as was done with the dogs seized from Michael Vick's Bad Newz Kennels in the former Atlanta Falcons quarterback's dogfighting case. *