Carthage, Mo. ? Four people from Oklahoma have been charged with assault for their alleged role in a deadly fight between two gangs at the Marian Days Celebration, a national religious festival held each year in southwest Missouri, police said.

Carthage Police Chief Dennis Veach said prosecutors filed first-degree assault and armed criminal action charges Friday night against Nguyen H. Nguyen, 18, of Oklahoma City; An N. Pham, 19, of Tulsa, Okla.; Nhatduy V. Ngo, 20, of Oklahoma City; and Khoa D. Nguyen, 20, of Yukon, Okla.

All four were being detained at the Jasper County Jail. Bond was set at $250,000 each.

“Within those four is the person who we believe is responsible for the fatal blow,” Veach said Saturday. “The prosecutor has the ability to file a murder charge whenever.”

Veach said Quoc Phu Pham, 22, of Wichita, Kan., was stabbed several times Friday morning and died from a wound in his chest. Three others were injured. Two were treated and released. One victim remained hospitalized.

Veach said the fight involved 15 to 20 people, all of whom were affiliated with a gang either from Oklahoma City or Wichita.

Afterward, Veach said, 20 people were ejected from the fair grounds at the Roman Catholic festival, believed to be the biggest annual gathering of Vietnamese and Vietnamese-Americans in the country. More than a dozen were detained, Veach said, including a 16-year-old girl who has been turned over to juvenile authorities for allegedly misleading investigators.

More than 50,000 people were expected to flock to the town of 12,500 for the event, which began Thursday and runs through today. Most stay in tents and use portable toilets and showers provided on the grounds, Veach said.