AURORA, Colo. -- A Colorado high school teacher was on administrative leave Thursday after he criticized President George W. Bush, capitalism and the United States' foreign policy in his geography class at Overland High School.

More than 100 students at Overland walked out of class in protest of the suspension Thursday morning. Then, additional students walked out to protest the teacher's remarks.

An Overland student went public Wednesday with a 20-minute recording of the incident, in which teacher Jay Bennish said there were similarities between what Bush said during his State of the Union address and "things that Adolf Hitler used to say."

The United States was "probably the single most violent nation on planet Earth," the social studies teacher also said on the tape, recorded by 10th-grade student Sean Allen.

"So these kids are going to have notes on why George Bush is related to Hitler and why the state of Israel was founded on violence and terrorism," Allen said on KHOW Radio Wednesday. "These kids are going to have notes on this and accept that as fact."

Cherry Creek School District spokeswoman Tustin Amole said officials are investigating the incident, but no disciplinary action has been taken. The investigation should take about a week.

"We do want teachers to express their opinions, but to put that in context and to provide opposing points of view," said Amole. "All discussion must be fair and balanced."

"(The suspension) is not a disciplinary action. It is to give us enough time to sit down and gather all the facts," said Amole.

Superintendent Monte Moses said that Bennish's presentation appeared to be unbalanced.

"Our policy calls for both sides to be present ... in the interest of intellectual discourse," he said.

Allen was not in class Thursday. He said he took the day off because of the negative feedback he's received since going public.