SANAA, Nov. 20 (Xinhua) -- A UN special envoy has urged the immediate and unconditional release of all UN personnel held by Yemen's Houthi group during a visit to Oman, said his office in a statement on Wednesday.

During his visit, UN Special Envoy for Yemen, Hans Grundberg, held talks with senior Omani officials in the Omani capital, Muscat, focusing on recent developments in Yemen and efforts to revive a political process aimed at ending Yemen's decade of civil war.

He thanked Oman for its "steadfast support" for UN mediation efforts and stressed the need for coordinated regional and international backing to pave the way toward a political settlement in Yemen.

During talks with Mohammed Abdelsalam, the Houthi chief negotiator in Muscat, Grundberg called for the release of all the remaining UN staff "arbitrarily detained" by the Houthi group.

In October, the United Nations secured the release of 12 UN foreign nationals in a mediation facilitated by Iran and Oman. The remaining detainees in Houthi prisons are Yemenis; although their precise number is unknown, sources estimate there are dozens.

The Houthis seized control of several northwestern Yemeni provinces in late 2014 when the civil war erupted, forcing the internationally recognized Yemeni government out of the capital Sanaa. Enditem