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.

All official movement of U.N. staff into or within Houth-held areas had been suspended to protect the safety of staff. The U.N. was actively engaging with senior Houthi representatives to demand the immediate and unconditional release of all its detained personnel and partners.

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

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.

Yemen's Huthi rebels have detained another group of UN personnel, a United Nations statement said on Friday, after 13 staff were held last June.