Syracuse University students trying to join Nu Alpha Phi, an Asian-American fraternity, were given demerits when they made mistakes during pledging, and a way to work them off.

There were push-ups and situps in the attic of the fraternity house, according to investigators and students. There were extended periods in a sitting position — knees bent, backs to the wall — that tested their physical strength and resolve. And on one frigid night in March, there were exercises outdoors in a park, with three pledges crawling and rolling in the snow with no gloves. One of them got frostbite on both hands and faced losing several fingers.

The number of Asian-American fraternities and sororities has grown over the last generation as the children and grandchildren of immigrants, feeling shut out of existing Greek organizations, began to create their own.

And as those groups have spread across the country, some have replicated not only the social networking of other fraternities, but also their excesses.

Last month, prosecutors in Pennsylvania announced that they planned to charge members of an Asian-American fraternity, Pi Delta Psi, in connection with a hazing-related death of a freshman at Baruch College in New York City during a retreat in the Poconos in December 2013. At least three other students have died during activities at Asian-American fraternities since 2005, and many more have been injured, resulting in a spate of criminal prosecutions, lawsuits and school disciplinary actions against fraternities and their members.

It is difficult to say whether abuses are more common in Asian-American organizations than in others. There are no official statistics on fraternity deaths and injuries across the United States. But people who have studied the issue say they have been surprised by the number of episodes, given that Asian-American fraternities occupy just a small corner of the collegiate Greek world.

“There shouldn't be this many deaths, this many cases, for this small number of organizations, chapters and members, ” said Walter M. Kimbrough, president of Dillard University in New Orleans, who is leading a task force on hazing prevention for the North-American Interfraternity Conference.

Across the country, there are more than 65 Asian-American fraternities and sororities, by some estimates, though most have small memberships and operate without permanent headquarters, professional staff or campus housing for students. Lambda Phi Epsilon International Fraternity, one of the largest with dozens of chapters, has experienced the most problems, including three deaths. Peter Tran, 18, a student at San Francisco State University, died after attending a fraternity party in 2013; the fraternity was subsequently expelled by university officials. Phanta Phoummarath, 18, a freshman at the University of Texas at Austin, died after drinking at a fraternity party in 2005; his family received a $4.2 million settlement in a lawsuit against Lambda Phi Epsilon and its members.

In a third case, in 2005, Kenny Luong, 19, a student at Cal Poly Pomona in California, died from fatal head injuries after playing football against Lambda Phi Epsilon members from the University of California, Irvine. Luong and his schoolmates were trying to start a chapter at their own college, and as a requirement, they had to face off against the existing chapter at Irvine in a game without any helmets or pads, the authorities said. In a lawsuit against the fraternity that ended with a $1.7 million settlement, Luong's family said the game was simply hazing in disguise, with the Irvine players often gang-tackling members of Luong's outnumbered team, even when they did not have the ball.

In the Baruch case, Chun Hsien Deng, 19, died after a ritual known as the “glass ceiling,” in which he was tackled by fraternity members while blindfolded and weighed down with a sand-filled backpack as he tried to cross a frozen yard, prosecutors said. After he was knocked out, they said, fraternity members delayed getting help and sought to cover up their involvement. Five of the 37 defendants are facing third-degree murder charges; the rest face charges that include assault, hindering apprehension and hazing.

Amid growing concerns over hazing, members of Lambda Phi Epsilon and other Asian-American fraternities and sororities say their organizations have actively promoted no-hazing policies, increased training for members and replaced potentially abusive pledging rites, such as strenuous runs around campus, with talks on Asian-American issues and walks for cancer.

In the Syracuse case involving frostbite, Nu Alpha Phi was banned from campus and two of its members, Tae Kim and Jeffrey Yam, who served as pledge masters, are awaiting trial on a misdemeanor charge of hazing. If convicted, they face up to a year in jail.

A lawyer for Yam could not be reached. James Hopkins, a lawyer for Kim, described him as a good student from a humble background who had no record and teaches chess to children. While he said it was unfortunate that the pledging student suffered frostbite, he said, “we are adamant that the same was not the result of criminal conduct on the part of Tae Kim.” (Ultimately, the student did not lose any fingers.)

Richard Cohn, a lawyer who represented the family of Luong, the student who died after the football game, said that hazing continues even when students are told they do not have to take part. Pledges are intimidated and fear they will be rejected by the fraternity if they do not participate in the rites, he said. “In practice, what is really happening is flat-out hazing despite the fact that they put together all kinds of legal documents that set forth rules against hazing and all the members are supposed to sign off on it,” he said.

The leaders of Lambda Phi Epsilon, Nu Alpha Pi and Pi Delta Psi did not respond to emails or calls seeking comment.

Brian Gee, director of risk reduction for another Asian-American fraternity, Pi Alpha Phi, says that any time there is a hazing-related death or injury “it's a huge setback” for leaders who are trying to make positive changes within their organizations and reinforces negative perceptions of them.

“We're always trying to do our best,” Gee said. “Every fraternity out there, Asian or not, has had setbacks. We do have very high expectations of our memberships to follow our policies. When violations are found, we do our best to hold chapters accountable. Sometimes that comes in the form of educational programming. Other times, it's sanctions or suspensions of chapters.”