Hebron, Occupied West Bank -- The Israeli army has arrested more than 20 Palestinians as it intensifies its search for three suspected kidnapped teenagers, triggering fears of a broader crackdown.

The Israelis disappeared late Thursday night after leaving their religious school in Kfar Etzion, an illegal settlement between Jerusalem and Hebron. Security sources said the trio, aged 16 to 19, were probably trying to hitchhike to their homes in central Israel and the occupied West Bank.

Hundreds of Israeli soldiers have been deployed, and on Saturday afternoon they could be seen searching on foot in several villages. Drones and surveillance balloons could be seen hovering over Hebron.

Two previously unknown groups, "Islamic State" and the "Brigade of the Free Men of Hebron," have issued notices claiming responsibility for the suspected kidnappings. Neither statement offered any proof of their validity.

The Israeli defense minister admitted on Saturday that he did not know whether the teenagers were alive.

"As long as we don’t know differently, our assumption is that they are," Moshe Ya'alon told reporters in a short press conference.

Their case has transfixed Israel, with television channels providing wall-to-wall coverage. It has been met with far less sympathy in Hebron—where many contrast it with the hundreds of Palestinian prisoners staging lengthy hunger strikes to protest their "administrative detention," a tool Israel uses to hold people indefinitely, without charge.

"I don’t know what happened here, but they say all Palestinians are responsible," said Mahmoud al-Karki, a resident of northern Hebron, where the army deployed and raided homes overnight.

"This is the life here. Now these new prisoners will disappear."

Raids and arrests

The army would not provide any details on the 20-plus Palestinians arrested. Lieutenant Colonel Peter Lerner, a spokesman, said that they were detained "in an attempt to close in on the inner circle of people involved in this."

"They'll come back tonight and arrest a hundred people for these three boys," said Marwan Qafishi, a pharmacist.

In a press conference on Saturday night, Israeli Prime Minister Benjamin Netanyahu reiterated that he holds the Palestinian Authority responsible for the teenagers' disappearance.

"We see Abu Mazen and the authority responsible for every attack that comes out of their territory," he said, referring to Mahmoud Abbas, the Palestinian Authority president.

Major General Adnan al-Damiri, the spokesman for the Palestinian security services, called a similar statement by Netanyahu on Friday a joke, telling a Palestinian news agency that the alleged kidnapping happened in an area under full Israeli control.

One of the three teenagers is a US citizen, and Secretary of State John Kerry called Abbas to discuss the case on Friday night.

Osama Hamdan, a senior member of the Hamas movement, said in a television interview on Saturday night that his group has no knowledge of the alleged kidnapping.

Also on Saturday, Israeli warplanes carried out two strikes in the southern Gaza Strip; no injuries were reported in either.

There were two reports of rockets fired from Gaza into Israel, one overnight, the other on Saturday evening; neither caused any damage or injuries.

PHOTO CAPTION

Israeli soldiers secure the area around a burnt car (background) on June 13, 2014, reportedly connected to the disappearance of three Israeli teen settlers in the West Bank town of Hebron.

Aljazeera