"We keep learning this over and over again — non-lethal means are useless when we are talking about a large number of people," a military source said.

The sources said the Army employed tear gas, rubber bullets as well as new products. One of them was called Scream, designed to emit a high-pitched sound that results in nausea.

"There was not one case in which these means actually stopped a large number of rioters," the source said.

As a result, the Army ordered main battle tank and automatic fire to stop the Palestinian rush toward the border. Scores of people were reported to have been killed or injured.

"The Israel Defense Forces used riot dispersion means in the area, as well as live fire with some injured," Israeli military spokesman Brig. Gen. Yoav Mordechai said. "These are not peaceful protests with flowers and love songs, but rather true provocations."