Israel said on Sunday that Hamas militants had abducted three Israeli teenagers in the West Bank, warning of "serious consequences" as it pressed on with a search and detained dozens of Palestinians.
The two 16-year-olds and a third man aged 19 disappeared on Thursday night in the West Bank, where they were seminary students in a Jewish settlement block.
"These teenagers were kidnapped and the kidnapping was carried out by Hamas members," Prime Minister Benjamin Netanyahu told reporters in English, referring to the Palestinian Islamist group that controls the Gaza Strip.
There has been no public claim of responsibility. Asked about Netanyahu's allegations, Sami Abu Zuhri, a Hamas spokesman in the Gaza Strip, stopped short of a clear denial or confirmation that it was involved.
Since the three vanished, apparently while hitchhiking, the Israeli army has carried out house-to-house searches, round-ups and interrogations in the Palestinian city of Hebron and outlying villages. The military said it detained around 80 suspects overnight and that the dragnet would spread elsewhere in the West Bank over the coming days. Palestinian officials put the number of people taken into Israeli custody so far at more than 100.
These included at least seven Hamas members of the Palestinian parliament and several prisoners recently released by Israel, the Palestinian officials said.
Israel identified the seminary students as Eyal Yifrach, Gil-ad Sha'er and Naftali Frankel, who also holds U.S. citizenship. In their last communication, one of the three managed to phone police on Thursday night to report that they were being kidnapped, according to an Israeli security official. "Naftali, your dad and mom and siblings love you endlessly, and you should know that the people of Israel are turning the world upside down to bring you home," Frankel's mother, Rachel, said in a televised statement outside the family home.
Thousands of Jews flocked to the Western Wall plaza in Jerusalem on Sunday evening to pray for the teenagers' return.
The crisis tests ties between the Israeli government and Palestinian Authority President Mahmoud Abbas, which were frayed by his power-sharing deal in April with Hamas, an Islamist group that advocates the Jewish state's destruction.
Gilad Erdan, a minister in Netanyahu's security cabinet, told Israel's Channel 2 television that Abbas's security forces were "willingly" helping search for the teenagers. Palestinian authorities acknowledged the cooperation, drawing Hamas censure.
Erdan played down the Palestinian role. Recovering the teenagers and tackling their captors would be "almost entirely based on the Israeli military and security services," he said.
In broadcast remarks at a cabinet session held, unusually, at Israeli military headquarters in Tel Aviv, where he has been overseeing the recovery efforts, Netanyahu said there would be "serious consequences" for the abduction of the teenagers.
Speaking later in English, he pledged that "Israel will act against the kidnappers and their terrorist sponsors and comrades".
Abu Zuhri, describing Netanyahu's remarks as "stupid comments", suggested that in casting blame on Hamas the Israeli leader was trying to draw the group into disclosing whether it was behind the teenagers' disappearance.
Palestinian militants have said they want to kidnap Israelis to win concessions from the Israeli government, and the current incident coincides with a hunger strike by some 300 Palestinian prisoners protesting against detention without trial.
More than 1,000 Palestinian prisoners were freed in 2011 in exchange for the release of Gilad Shalit, an Israeli soldier held captive in the nearby Gaza Strip for more than five years.
Netanyahu said Abbas's alliance with Hamas had emboldened militants in the West Bank, where the Western-backed Palestinian leader's Fatah movement has held sway, and demanded he do "all that is necessary" to resolve the crisis. The United States said on Friday that it had also urged Abbas to help Israel.
Additional reporting by Ari Rabinovitch, Ali Sawafta and Nidal al-Mughrabi; Editing by Sophie Hares and Stephen Powell