The U.N. Palestinian refugees agency warned Tuesday that conditions in the Jenin refugee camp in the occupied West Bank are deteriorating catastrophically, describing residents as having "endured the impossible."

The Israeli military launched a major offensive in the West Bank on Jan. 21 aimed at rooting out Palestinian resistance groups from the Jenin area.

Earlier Monday, Palestinian authorities raised "ethnic cleansing" accusations while a U.N. special rapporteur blamed Israel of 'genocidal intent' after it killed at least 70 Palestinians in the territory since the start of the year.

The operation has also seen troops leveling buildings in a refugee camp adjacent to Jenin.

"The camp is going into a catastrophic direction," UNRWA spokeswoman Juliette Touma told reporters in Geneva.

"Large parts of the camp were completely destroyed in a series of detonations by the Israeli forces. It is estimated that 100 houses were destroyed or heavily damaged," she said, speaking from Amman.

"The residents of this particular camp have endured the impossible."

She added: "This detonation that happened Sunday was when children were supposed to go back to school.

"When it comes to UNRWA, 13 schools in the camp and the surrounding areas continue to be closed. That affected 5,000 kids in that area."

Touma said UNRWA's services inside Jenin camp have been interrupted for several months and stopped completely in early December.

UNRWA said it received no prior warning of the detonations, as contact between staff and Israeli authorities is no longer permitted.

After Israel accused UNRWA of providing cover for Hamas members, legislation severing ties with the agency came into force Thursday – a move likely to hamper the agency's vital services after Israel's 15-month genocidal war in Gaza.

The agency is banned from operating on Israeli soil and contact between it and Israeli officials is also forbidden.