UNITED NATIONS (AP) — At least 19 U.N. employees were detained by Iranian-backed Houthis during raids on U.N. offices in Yemen’s capital, the United Nations said Tuesday, a higher number than originally reported.

U.N. spokesman Stephane Dujarric said 18 of those being held are Yemeni staffers and one is an international employee. He called for all to be released immediately.

Sunday’s raids on offices of the United Nations’ food, health and children’s agencies in Sanaa followed Israel’s killing of Houthi Prime Minister Ahmed al-Rahawi and several Cabinet ministers in an airstrike on Thursday.

The Houthis have been engaged in a civil war with Yemen’s internationally recognized government, backed by a Saudi-led coalition, since 2014, when they took control of Sanaa and most of northern Yemen.

Hopes for peace talks vanished after the Hamas-led attack in southern Israel on Oct. 7, 2023, which led to Israel’s retaliatory war in Hamas-run Gaza. The Houthis started attacking ships in the Red Sea in support of Palestinians in Gaza. That sparked U.S. and Israeli retaliatory strikes in areas the rebels control in Yemen.

The raids were the latest in a long-running Houthi crackdown on the U.N. and other international organizations as well as diplomats working in rebel-held areas. Dujarric said the Houthis previously had detained 23 U.N. employees, holding some since 2021.

U.N. special envoy Hans Grundberg just ended a visit to Oman’s capital, Muscat, where he met Houthi chief negotiator Mohammed Abdelsalam and representatives of the diplomatic community, the U.N. spokesman said.

Dujarric said the envoy reiterated the U.N.’s strong condemnation of the detentions and forced entry into its offices, warning that the Houthi action seriously endangers the U.N.’s ability to deliver aid to the people of Yemen, the Arab world’s poorest country.