The Yemen government and Shiite rebels are hampering efforts to channel aid to tens of thousands of civilians cut off or displaced by fighting, Human Rights Watch said on Wednesday.

The Yemen authorities `severely restricted humanitarian access` to the restive northwestern region of Saada while Shiite rebels have prevented humanitarian access to areas they control, HRW said in a 50-page report.

`As of October 2008, up to 70,000 people in remote areas and towns remained outside the reach of aid agencies,` it said.

`The government imposed an information blackout and blocked the movement of commercial goods, including basic foods and fuel, an apparent act of unlawful collective punishment,` since May 2005, it added.

HRW said that the report -- titled `Invisible Civilians: the Challenge of Humanitarian Access in Yemen’s Forgotten War` -- was based on three weeks of investigation in Sanaa in July.

The rights watchdog inteviewed displaced persons and aid agencies but was not granted permission to visit Saada, it said.

In August, the International Committee of the Red Cross (ICRC) expressed grave concern over the living conditions of 15,50O Yemenis displaced by fighting between government forces and the rebels.

Thousands have been killed in the fighting between the army and the Zaidi rebels, known as Huthis after their late commander Hussein Badr Eddin al-Huthi who was killed by the army in September 2004.

His brother Abdul Malak, the current leader of the rebels, reportedly agreed in August to a 10-point offer by President Ali Abdullah Saleh to end the war.

These reportedly included a ceasefire and the reopening of blocked roads.

Saleh announced on July 17 that the revolt which broke out in 2004 was over but there has been no confirmation from Huthi. Local military and tribal sources have since reported sporadic clashes between government forces and rebels in the area.

The rebels have been fighting to restore the Shiite Zaidi imamate which was overthrown in a 1962 republican coup.