Protesters say the demonstrations are peaceful but the IDF disagrees
The Israeli Defence Force has barred Israelis and foreigners from two West Bank villages, the scene of protests against Israel's "separation wall".
Soldiers have posted flyers declaring areas around the villages of Bilin and Nilin are "closed military zones".
The restriction applies to the areas every Friday, the day that protests are held, for the next six months.
Activists have been protesting against the barrier for five years in what they say are mostly peaceful demonstrations.
But the Israeli Defence Force says it considers the protests to be "violent and illegal".
Israel says the barrier was established to stop Palestinian suicide bombers entering from the West Bank.
But Palestinians point to its route, winding deep into the West Bank around Israeli settlements - which are illegal under international law - and say it is a way to grab territory they want for their future state.
In 2004, the International Court of Justice in The Hague issued an advisory ruling that the barrier was illegal and should be removed where it did not follow the Green Line, the internationally recognised boundary between the West Bank and Israel.
Around 100 members of the security forces have been injured policing the demonstrations, a spokesman said.
"Every week violent, illegal riots take place in the area of Nilin and Bilin, during the course of which members of the security forces are wounded and heavy damage is caused to the security fence and to public property," a statement from the IDF said.
"In an effort to prevent the inciters of these riots from reaching the area in which the riots take place, three weeks ago, OC Central Command signed an order designating the area between the fence and the villages of Nilin and Bilin as a closed military zone."
The statement said residents of the villages were exempt from the order.
Protests at the "separation barrier", a fence between Palestinian land and Israeli settlements, had attracted young Israelis and peace activists from around the world.
Some demonstrations had also been attended by stone-throwing Palestinian youths.
Israeli security services have fired tear gas, stun grenades, rubber bullets and on occasion live rounds at protesters.
There have been two fatalities among protesters and an American peace activist suffered brain damage after being hit by a teargas canister.