The Sahara Press Service (SPS) owned by the Polisario Front reported that the movement's forces bombed the Guerguerat region on Saturday evening.
The news agency quoted a military source as saying that "the Saharawi army launched four rockets in the direction of … Guerguerat."
The SPS pointed out that attacks took place along the security wall that separates the Polisario forces and Moroccan troops stationed in the vast desert lands.
A senior Moroccan official told Agence France-Presse that the attack did not disrupt commercial traffic in the area.
Morocco has been in conflict with the Algeria-backed separatist Polisario group over the Western Sahara since 1975, after the Spanish occupation ended. It turned into an armed confrontation that lasted until 1991 and ended with the signing of a ceasefire agreement.
Rabat insists on its right to govern the region, but proposed autonomous rule in the Western Sahara under its sovereignty, but the Polisario Front wants a referendum to let the people determine the future of the region. Algeria has been supporting the Front's proposal and hosts refugees from the region.
The 1991 ceasefire came to an end last year after Morocco resumed military operations in the El Guergarat crossing, a buffer zone between the territory claimed by the state of Morocco and the self-declared Sahrawi Arab Democratic Republic, which the Polisario said was a provocation.
By launching the operation, Morocco "seriously undermined not only the ceasefire and related military agreements but also any chances of achieving a peaceful and lasting solution to the decolonization question of the Western Sahara," Brahim Ghali, leader of the Polisario Front, said in a letter to the UN.
Late last year, Morocco agreed to normalise ties with the occupation state of Israel in return for the US' recognition of its sovereignty over the Western Sahara.