The UN's human rights office on Friday, June 27 urged Israel and its adversaries to exercise restraint amid a crackdown on Palestinians during a hunt for three Jewish teenagers missing in the West Bank, Agence France-Presse reported.

"Clearly these boys need to be found, that's totally understandable, but the scale of operations and the number of people they are affecting is deeply disturbing," said its spokesman Rupert Coville. "We reiterate our call for strict adherence to international law by all relevant actors and join others in their call for restraint," he told reporters.

The three teenagers went missing on June 12 near an Israeli settlement bloc close to the city of Hebron. There have been no claims of responsibility, but Israel has accused the Palestinian Islamist movement Hamas of kidnapping them.

The Israeli army has launched a vast hunt for them, dubbed Operation Brother's Keeper. Several Palestinians have been killed and dozens wounded so far.

The mothers of the three teenagers travelled to Geneva this week and held a private meeting with deputy UN human rights chief Flavia Pansieri.

Colville said the loss of life during the operation was alarming, as were the spiking tensions in the West Bank. "We call for prompt and thorough investigations, and prosecution of the perpetrators in cases where there has been excessive use of force," he said.

More than 380 Palestinians, two-thirds of them Hamas members, have reportedly been arrested by the army during the search, though Coville put the number at around 500.

Hundreds of homes have also been searched, media offices, universities and welfare organisations raided, at least 13 buildings demolished and water cisterns drained or damaged, Colville said.

"We are also concerned about reports of damage to property and theft during these operations, especially house-to-house searches, and their traumatic effect on children and families," he added.