By Gary Robertson

RICHMOND, Virginia (Reuters) - Four men were charged with involuntary manslaughter after two Virginia State University students drowned in the Appomattox River during an initiation ritual this spring, police said on Wednesday.

The men have already been charged with hazing after seven male students were swept downstream on April 20 as they tried to walk across the river as part of their initiation into an unauthorized college social club known as "Men of Honor," police said.

Some of the students were pulled to safety and others drifted to shore. Two 19-year-old students, Marvell Edmondson and Jauwan M. Holmes, drowned and their bodies were later recovered.

James A. Mackey Sr., 35; Eriq K. Benson, 19; Cory D. Baytop, 26; and Charles E. Zollicoffer II, 29 - all connected with the "Men of Honor" group - each face two counts of involuntary manslaughter and five counts of hazing, said police in Chesterfield County, Virginia.

University officials said the "Men of Honor" group was unsanctioned and the school condemned the initiation rite as intolerable and outdated.

The university has convened a task force which is in the process of developing stronger anti-hazing measures.

Dangerous college hazing rituals have attracted more attention since the 2011 beating death of 26-year-old Florida A&M University drum major Robert Champion during a band trip. That death was ruled a homicide and led to felony charges against a number of band members.

(Editing by Colleen Jenkins and Richard Chang)