The United Nations on Friday suspended all travel into areas held by Yemen’s Houthi rebels after more of their staff were detained by the rebels.

In June, the Houthi's detained 11 employees from Yemen as the rebels kept cracking down on areas under their control.

The United Nations said on Friday that the Houthis who control northern Yemen had detained an unspecified number of U.N. personnel, and it was suspending movement in all Houthi-held areas while seeking the detainees' immediate release.

The United Nations has announced that the Houthis, controlling northern Yemen, have detained several UN personnel. In response, the UN has suspended staff movement in Houthi areas while demanding their release.

The move will authorize harsher penalties on the Iran-backed group, which has attacked Israel and disrupted global shipping trade in the Red Sea for over a year.

The United Nations (UN) says it has suspended all movement in Houthi-held areas of Yemen after a number of UN personnel were detained by the armed group in the capital, Sanaa. The UN said that it was actively engaging with senior Houthi officials to try to secure the release of all its detained employees.

The United Nations said on Friday that Yemen's Houthi rebels have once again detained its personnel in the war-wracked country. They were detained in areas controlled by the Iran-backed militia, the UN Yemen office said.

The UN said on Friday it was suspending “all official movements” in Houthi-controlled parts of Yemen after the rebel group detained a number of people employed by the world body. The office of the resident UN co-ordinator for Yemen called for the “immediate and unconditional” release of all its detained staff held in the country.