Israel has accused Hamas militants of abducting three Israeli teenagers who went missing from the West Bank.
Prime Minister Benjamin Netanyahu told his cabinet that those responsible came from the same organisation that formed a Palestinian Unity government.
The two 16-year-olds and a 19-year-old, one of whom Israel says also holds US citizenship, went missing on Thursday as they reportedly tried to hitch-hike back from lessons.
One Hamas spokesman dismissed Israel’s accusations as “stupid”.
Other Palestinian officials say they are helping in the search.
“There is a failure in Israel’s security system, because the people went missing in a zone which is totally secured and controlled by the Israeli authorities. They were in a strategic area which has Israeli military camps,” said Abbas Zaki, an official with the Fatah movement.
Israeli media say the teenagers disappeared near Gush Etzion, a block of Jewish settlements between the predominantly Palestinian towns of Bethlehem and Hebron.
Israel’s military said it had detained around 80 Palestinian suspects as it carried out house-to-house searches in the Hebron area.
Some 2,500 soldiers have been mobilised in the search, in the biggest such operation in the West Bank for years.
The crisis has put the biggest strain on Israeli-Palestinian relations since the power-sharing deal was struck between Hamas and the Palestinian Authority in April.