But despite the protests and mounting criticism of the project from the United States, a new poll found that Israeli public support for the barrier remained overwhelming.
Troops burst into the house of the Amar family in the village of Mashah as well as the garden where the protestors had erected a tent, activists and military sources told AFP. Authorities had declared the area "a closed military zone".
Those arrested included 41 members of the International Solidarity Movement (ISM) and six Israelis. Some of the foreign activists were from the United States, Britain, France, Italy, Germany and Sweden.
Lysander Puccio from New York told AFP the group of 47 was rounded up by the army and taken to the police station of the nearby Jewish settlement of Ariel.
"An Italian, an Israeli and a Palestinian are being interrogated inside the police station, while the rest of us are waiting in the parking lot," she said.
A police spokesman said that the interior ministry had been informed of their arrest with a view to their possible expulsion.
"We were trying to protect a house from being isolated between the wall which is being constructed by the Israeli government and a fence surrounding the nearby Jewish settlement," the activist explained.
"Once they removed us, they bulldozed right through the property," she said.
"The Amar family will from now on be allowed to leave this house only three times a day. What the army is trying to do with this family has nothing to do with protecting Israel. This is a form of transfer," Puccio charged.
The Palestinians and rights groups charge that the barrier, which consists either of a strong fence or a concrete wall, is an attempt by Israel to annex the West Bank's "bread-basket" and unilaterally determine the borders of a future Palestinian state.
The ISM has been leading an aggressive campaign in recent weeks to protest against the fence as well as roadblocks hampering freedom of movement in the West Bank.
In previous protests US activist Rachel Corrie was crushed to death by an Israeli army bulldozer in the Gaza Strip (news - web sites) town of Rafah in March and fellow ISM member Tom Hurndall from Britain was declared clinically dead after being shot in the same area a month later.
Tuesday's arrests came as a senior US official told AFP the United States is considering punishing Israel for the construction of the barrier in Palestinian areas.
The plan would withhold from Israel US loan guarantees in the amount the Jewish state spends on the construction east of the official Green Line division between Israel and the West Bank, the official said.
Israel says the barrier is essential to prevent Palestinian militants infiltrating from the West Bank to carry out anti-Israeli attacks.
"It is something that is being looked at," the official told AFP on condition of anonymity.
"Real questions have been raised about the fence and we're discussing how we should express our concerns in a concrete way."
The official said the proposal was still being debated by the White House and the State Department and that no decision on it would likely be made before September.
Shortly after the official spoke, Secretary of State Colin Powell (news - web sites) stressed that US concerns about the construction of the barrier, which the Palestinians claim is an attempt to establish the boundaries of their future state outside the negotiating process, were real.
And, Powell noted with disapproval that along some stretches, the barrier is being built in Palestinian territory, jeopardizing the potential success of the US-backed "roadmap" for peace.
Despite the controversy, a survey by researchers at Tel Aviv University found that support for the fence remains strong among the Israeli public.
Eighty percent of respondents said that they backed the principle "of a fence separating Israel and the Palestinians" and only 15 percent were against.
The approval figure fell to 71 percent when asked if the project should continue in the light of US objections.
