Israeli troops on Monday rounded up dozens more senior Hamas activists and killed a Palestinian in a clash with stone throwers — part of a feverish search for three kidnapped Israeli teenagers who Israel alleges were seized by the Islamic militant group.

The West Bank abductions came at a time when Israeli-Palestinian tensions were already running high over Palestinian President Mahmoud Abbas' formation of a unity government that is backed by his former rival Hamas.

With senior Israeli officials now calling for crackdown on Hamas and perhaps even the Western-backed Abbas, there is growing concern of a major escalation.

It's not clear how far Israeli Prime Minister Benjamin Netanyahu will go in trying to dismantle the Hamas organization in the West Bank, considering the risk this might further destabilize the West Bank. Despite Netanyahu's verbal attacks against Abbas, he does not want to see a collapse of the pragmatic Palestinian self-rule government in the West Bank.

Senior Israeli Cabinet ministers were to meet Monday. The government is reportedly weighing a series of measures, including the deportation of Hamas leaders from the West Bank to Gaza, where Hamas remains the de facto power, despite the unity deal.

The three Jewish seminary students went missing late Thursday while hitchhiking at a West Bank bus stop near the Palestinian city of Hebron. They were en route home, two to West Bank settlements and the third, an American citizen, to a small community in Israel.

Large numbers of Israeli troops have been involved in a massive search since then, going house to house in some areas.

Israeli forces have arrested more than 150 Palestinians, most of them from Hamas, over the past four days. Among those detained were 10 Hamas legislators — or one-third of the Hamas representatives from the West Bank in the long-defunct Palestinian parliament.

Netanyahu has alleged that Hamas carried out the kidnappings, but provided no evidence. He has also held Abbas responsible for the fate of the teens and claimed the unity government created the atmosphere for the kidnappings.

Netanyahu called Abbas on Monday, a fairly rare contact between the two leaders, the Israeli premier's office said. Netanyahu called on Abbas to help with efforts to rescue the abducted teens and arrest the Hamas kidnappers.

"The Hamas kidnappers came from territory under Palestinian Authority control and returned to territory under Palestinian Authority control," Netanyahu told Abbas.

Abbas aides have rejected Netanyahu's contentions that the Palestinian self-rule government is ultimately responsible for the abductions, saying that Israel is in overall control of the West Bank. The junction where the teens were last seen is under Israeli control and is commonly used by soldiers and Jewish settlers.

Abbas had remained silent since Thursday, but issued a statement Monday.

"The Palestinian leadership condemns the series of events over the last week, beginning with the kidnapping of the three Israeli teens and ending with a series of Israeli violations," the statement said.

Among the violations, the statement listed the arrests and the killing of a 20-year-old Palestinian by Israeli army fire early Monday, during a confrontation between stone throwers and soldiers.

The abductions have placed Abbas in a bind.

He has repeatedly assured the U.S. and Europe that despite his alliance with Hamas, his forces in the West Bank would not halt their security coordination with Israeli troops. Targets of such coordination have been militants, including from Hamas.

Despite the heated rhetoric of recent days, Palestinian security chiefs have worked with Israel to try to locate the missing teens, Palestinian officials have said.

At the same time, Abbas cannot use the security coordination as a defense against Netanyahu's verbal attacks against him. Such coordination is widely unpopular among Palestinians and, if highlighted publicly, could torpedo Palestinian reconciliation efforts.

Netanyahu has used the abductions to try to discredit the unity government, which is made up of technocrats loyal to Abbas and won initial support from Europe and the U.S.

One of the missing teens, 16-year-old Naftali Fraenkel, has family in the U.S.

Fraenkel's grandparents moved to Israel in 1956 from Flatbush in Brooklyn, New York, and Fraenkel was born and raised in Israel, said Ittael Fraenkel, his aunt.

She said many of his close relatives live in Brooklyn and other parts of New York, and that his uncle's synagogue and other synagogues in Brooklyn were organizing prayer vigils.

The case has riveted the nation's attention, receiving around-the-clock coverage.

Palestinian militants have repeatedly threatened to kidnap Israelis, hoping to use them as bargaining chips to win the release of prisoners held by Israel. The abductors have not issued demands, so it is not clear what their objectives are.

Currently, dozens of Palestinians held by Israel are on an open-ended hunger strike to try to force Israel to end the practice of "administrative detentions" without charges or trial. The hunger strike began April 24, and since then dozens of participants have been hospitalized. Netanyahu is trying to fast-track a bill that would allow force-feeding them.

Hamas has praised the kidnappings, but has stopped short of claiming responsibility.

Several claims of responsibility have emerged in recent days, including one by a purported al-Qaida offshoot, but none could be authenticated.

For Hamas in the West Bank, the arrest sweep is another serious blow. Since the movement seized Gaza by force in 2007, wresting control there from Abbas, it has been targeted in crackdowns in the West Bank, both by Israel and the Palestinian Authority.

With the latest arrests, 19 of 30 Hamas legislators in the West Bank are now in Israeli custody.