A Moroccan military tribunal on Wednesday postponed indefinitely the trial of 23 Sahrawis implicated in the killing of security forces members during clashes in the Western Sahara two years ago.

The clashes in which 13 people were killed, all but two from the security forces, broke out as the forces moved to dismantle the Gdim Izik camp near Laayoune, the territory's main city, in November 2010, the authorities say.

The 23 Sahrawis were arrested during the unrest, and are accused of "assassinations" as well as taking part in an "unauthorised gathering" and "damaging public property."

Wednesday's hearing lasted just a few minutes, with the trial adjourned indefinitely, an AFP journalist at the tribunal reported.

Some 20 relatives of the accused staged a protest outside the tribunal.

At dawn on November 8, 2010, Moroccan security forces moved to dismantle the Western Sahara camp where thousands of local Sahrawis were living.

The intervention sparked clashes that spread to nearby Laayoune, where businesses and public buildings were looted and torched.

The authorities said 13 people were killed in the unrest, 11 from the security forces, while the Algeria-based Polisario Front separatists said dozens of people lost their lives.

Morocco annexed the former Spanish colony in 1975, in a move never recognised by the international community.

The Polisario Front launched its struggle for independence even before the annexation, with the resulting war lasting until 1991 when the UN brokered a ceasefire, but a settlement of the conflict still remains elusive.

The UN peace envoy for the Western Sahara, Christopher Ross, is due to begin a three-week visit to Europe and north Africa on Saturday in a bid to revive the stalled negotiations between the two sides.