A Palestinian official said the arrests of about 80 Palestinians in the occupied West Bank on Sunday by the Israel as an extended manhunt to find three abducted Israeli teenagers a violation of international laws.

The 80 Palestinians, among them top members of Hamas, and members of the group's Legislative Council, were arrested in and around Hebron and across the West Bank in a joint military, police and Shin Bet operation, according to an Israeli military statement.

"The arrest campaign is unjustified and an act of collective punishment," Palestinian minister of prisoners' affairs Shawqi al- Ayssa said on Sunday.

In a press statement, Hamas spokesman Sami Abu Zohri urged the international community to intervene to stop what he claimed " Israel's crimes" against the Palestinians.

Meanwhile, the Israeli military imposed closures on Palestinian cities in the West Bank, centered on the city of Hebron and its environs beginning at midnight on Sunday, and a closure of Bethlehem went into effect hours later.

A senior military source said that the closures and arrests aimed at strengthening the efforts to collect intelligence on the whereabouts of the three Jewish teens. The current massive manhunt involves more than 2,000 military forces.

The three kidnapped yeshiva students, two of them aged 16 and the other 19, who attended a religious high school in the West Bank, were kidnapped by a terrorist organization when they were returning to their homes for the weekend Thursday night.

A HAMAS PLOT

Israeli Prime Minister Benjamin Netanyahu on Sunday accused the Palestinian Islamist organization Hamas were behind the missing of the three Israeli teenagers.

"Today I can say that the kidnap was executed by Hamas," Netanyahu said at the start of a weekly cabinet meeting, which was relocated to the Defense Ministry in Tel Aviv. "This has grave consequences," he warned. "The aim of this activity is to tighten the circle of intelligence," an army source told Ynet news website.

On Saturday night after lengthy consultations with his defense chiefs at the nation's military headquarters in Tel Aviv, Netanyahu said in a televised statement that his government was doing "everything it can and more" to bring the victims home, demanding that Palestinian President Mahmoud Abbas do "everything that's required" to assist these efforts.

"We view Abbas and the Palestinian National Authority as responsible for any attack against Israel launched from their territory, either the West Bank or the Gaza Strip," said Netanyahu.

He dismissed the Palestinian claim that it bears no responsibility because the abduction took place in a West Bank area where Israel has full security control as "essentially unfounded."

Netanyahu said the abduction illustrated the inherent dangers of a newly sworn-in unity government sponsored by Abbas' Fatah party and Islamist group Hamas, reminding that his government has warned for months against the "harsh consequences" of the alliance.

Defense Minister Moshe Ya'alon said on Saturday the three kidnapped Israelis were presumed to be alive.

"At the moment we are working under the assumption that they are alive," he told the media after a meeting with top military brass at a territorial brigade's headquarters in the West Bank.

ABBAS OFFERS SEARCH HELP

Meanwhile, Palestinian leader Abbas has instructed his security forces to help searching the three kidnapped on Thursday night in southern West Bank.

Abbas met with U.S. Consul in Jerusalem Michael Ratney in the West Bank city of Ramallah, and informed him of the search efforts, a Palestinian official said.

"President Abbas told Ratney that although the three Israelis were disappeared in area that is under the full Israeli security control in southern West Bank, the security forces will help finding them," he added.

The Palestinian official also said that the United States refused to hold the Palestinian National Authority responsible for what had happened, but called on the Palestinians to move on all levels to resolve the problem.

UN CONDEMNATION

Also on Saturday, UN Secretary-General Ban Ki-moon condemned the West Bank abduction, and called for their immediate release in a statement issued by his spokesperson.

Ban expressed "his deep concern about the trend toward violence on the ground and attendant loss of life, including today of a child in Gaza as a result of a recent Israeli airstrike."

"The Secretary-General urges all to exercise restraint and lend their urgent support for the release and safe return of the three youths," the statement said. Endi