IDF officials confirmed soldiers used a new non-lethal tactic in the West Bank village of Bilin, where hundreds of demonstrators rallied against Israel's separation barrier.

The officials said the weapon uses voice frequencies to disperse crowds. Israel developed the technology over the past four years, but had never used it in a live situation before Friday, they said.

No further details were immediately available.

An Associated Press photographer said a military vehicle arrived toward the end of the demonstration, which lasted several hours and became violent at times.

Clubs and stun grenades also used

Located about 500 meters (a quarter mile) from the demonstration, the vehicle emitted several bursts of sounds, about one minute in length each time. Although the sound was not loud, it caused people to cover their ears and grab their heads in discomfort.

About 400 people, including Palestinians and foreign and Israeli activists, participated in the demonstration, marching toward a site where Israel is building its West Bank separation fence.

The crowd was prevented from reaching the site, and began rioting and throwing rocks at soldiers, the army said.

In addition to the sound machine, soldiers used other means to disperse the crowd, including clubs and stun grenades.

Israel has completed about one-third of the planned 425mile (680-kilometer) barrier, which it says is necessary to keep out suicide bombers from the West Bank.

Palestinians say the barrier is a thinly veiled land grab because it dips into the West Bank in some areas