RCMP said Monday that the charges include assault, assault with a weapon and assault causing bodily harm.
The alleged victims had severe bruising and one boy had muscle damage to his leg and buttocks.
Sgt. Craig Cleary said police were called after a bush party Sept. 6 outside the community of Lanigan, east of Saskatoon.
The party was a freshman gathering that police said included the hazing of some Grade 9 and 10 students by high school seniors.
"Some of those hazing rituals included such things as pouring of chocolate syrup, eggs, flour on some of the students," Cleary said.
"The ones that definitely concerned us of a more severe nature were those involving a paddle and that paddle was a modified goalie hockey stick with the blade cut off. That paddle was used in assaulting a number of different male youths that had attended to the party."
Cleary said there were more than 150 people at the party.
Nine of the accused and the victims are boys. Two of the accused are 18-year-old men.
Cleary said police are aware of five alleged victims, but believe there are more teens who haven't or won't come forward.
"The police investigators are speaking to a lot of the students, but the level of co-operation from the families of the potential victims isn't quite the same as the ones that have actually come forward," he said at Saskatchewan RCMP headquarters in Regina.
"If any more victims do come forward, obviously they would be spoken to and if there's enough evidence to lay a charge, then charges would be laid."
Cleary said police were working with the high school.
Lanigan Central High School and the Horizon School Division had sent a letter to parents Sept. 5 warning them about hazing before the party.
"Hazing is a form of abuse. Do you know that hitting someone with a paddle is assault?" the letter said.
"If initiation activities are going on, they are in full contradiction to anti-bullying strategies that we teach at school. Your child knows full well what bullying is about."
The Sept. 5 letter also urged parents to research Rehtaeh Parsons and Amanda Todd.
Rehtaeh's family says she was tormented after a digital photograph of her allegedly being sexually assaulted in November 2011 was passed around her Nova Scotia school. She was 17.
Amanda, a B.C. girl who was tormented online after being sexually exploited, committed suicide last year after posting a heartbreaking video about her treatment at the hands of relentless bullies. She was 15.
In a follow-up letter, the school said it's saddened and shocked by the stories coming from the community about the party.
"Even though that event happened outside of school hours, the fallout has come to the school," wrote Marc Danylchuk, director of education for the Horizon School Division.
"All of our students deserve support to move through the effects of this event."
The follow-up letter also said the school division wants to completely eliminate such hazing.
"Please take the time to educate yourselves regarding hazing in order that you can make a strong stand for yourself and your family against any type of hazing activities," the letter said.
"How can we work together to ensure there is no longer initiation activities and parties?"
The accused are to appear in Humboldt provincial court Oct. 21.
— By Jennifer Graham in Regina
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