(CNN) -- Nine Central Washington University students hospitalized this month after an off-campus party were sickened by "Four Loko," a caffeinated malt liquor also known as "blackout in a can," according to a police investigation.
Investigators concluded that none of the students were drugged or given alcohol without their knowledge and no sexual assaults occurred, according to a school statement.
The findings convinced university President James Gaudino to ban "alcohol energy drinks" from his campus.
"We need to make sure that we're sending a strong message to students about the dangers of alcohol energy drinks and we need to know more about the way it affects health and behavior," Gaudino said.
The drinks are "a binge-drinkers dream because the caffeine and other stimulants allow a drinker to ingest larger volumes of alcohol without passing out," the chairman of the school's physical education department said.
Video: 'Blackout in a can'?
Video: Women drugged at college party
Video: College students drugged at party
"Being able to feel the effects of tiredness, loss of coordination and even passing out or vomiting are the body's defenses against consuming doses of alcohol that will kill you," professor Ken Briggs said.
"Regardless, once the blood alcohol level reaches a certain level, you can drop like a box of rocks."
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Police found the underage students passed out and "very intoxicated" at a party attended by about 50 students in Roslyn, Washington, on October 9, the police report said.
Each students consumed "Four Loko," while some mixed the canned drinks with other alcohol, including vodka, the report said.
Washington State Attorney General Rob McKenna is calling for federal food regulators to ban the beverages.
"They're marketed to kids by using fruit flavors that mask the taste of alcohol and they have such high levels of stimulants that people have no idea how inebriated they really are," McKenna said. "They're packaged just like non-alcoholic drinks, but include a dangerous dose of malt liquor."
The maker of "Four Loko" -- Phusion Projects of Chicago, Illinois -- told CNN the company is doing "all we can to ensure that our products are consumed safely and responsibly."
"The unacceptable incident at Central Washington University, which appears to have involved hard liquor, such as vodka and rum, beer, our products, and possibly illicit substances, is precisely why we go to great lengths to ensure our products are not sold to underage consumers and are not abused," a company statement said.
