Earlier this week, a group of armed gunmen looted four trucks carrying UN Children's Fund (UNICEF) aids for the internally displaced people (IDP) in the northern province of Sa'ada, Interior Ministry reported on its website.

Gunmen of Al-Osaimat tribe believed to be Houthi affiliates in Amran province, north of Sana'a, intercepted the aid convoy and looted the aid worth 44,000 U.S. dollars for the IDPs in Sa'ada, the same sources said, adding that security forces were hunting down the groups to arrest them and regain the aid convoy.

Since 2004 Yemen has witnessed intermittent clashes between government troops and the Houthi rebels whom the government accused of seeking to re-establish the clerical rule overthrown by the 1962 Yemen's revolution.

However, both sides repeatedly accused each other of breaching February cease-fire agreement to end the conflict.

On Aug. 27, the Yemeni government and northern Shiite rebels signed another agreement in the Qatari capital Doha to cement the fragile ceasefire in northern Yemen.