(CNN) The leader of the Western Sahara's independence movement has vowed to end a 29-year-old ceasefire with Morocco, citing recent Moroccan border operations as a provocation.
Brahim Ghali, leader of the independentist Polisario Front, announced the group will no longer abide by the commitment of the decades-long truce in the area, said Sahara Press Service, the group's news agency, on Saturday.
Morocco, which says it continues to support the ceasefire, announced last week that it would resume 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.
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," Ghali said in a letter to the UN.
The Western Sahara is a long-disputed territory to the southwest of Morocco controlled mostly by the Moroccan state, which occupies about 75% of the territory, according to the CIA World Factbook. Morocco and the Polisario Front fought over the territory after Spain gave up the rule in 1976 and Mauritania withdrew their claim of control in 1979. After negotiating a truce in 1991, the UN has recognized the area as "non-self-governing territory."
Morocco's Foreign Ministry has said its border operation was intended to "consolidate the ceasefire" in response to Polisario Front allegedly blocking the movement of people and goods and harassing UN troops at the crossing.
"Morocco remains firmly attached to the preservation of the ceasefire, noting that the operation carried out by the Royal Armed Forces aims precisely to consolidate the ceasefire by preventing the recurrence of such serious and inadmissible acts that violate the military agreement and threaten regional security and stability," the ministry said.
The UN however has denied that their troops were harassed. "MINURSO has engaged peacefully at Guergerat with both the demonstrators supported by the Polisario Front and with the Morocco army with the aim of reducing tensions, since the beginning of the demonstrations on 21 October," UN spokesperson Nick Birnback said in a statement.
The Sahara Press Service said on Saturday that the Polisario Front also launched attacks against the Royal Moroccan Army in the Western Sahara, "causing loss of lives and equipments and disrupting its military plans." The Moroccan government has not yet commented on these claims.
The UN, which maintains a peacekeeping mission in the Western Sahara, MINURSO, said it made attempts to convince all parties to avoid an escalation of hostilities and preserve the ceasefire but was unsuccessful.
"The Secretary-General remains committed to doing his utmost to avoid the collapse of the ceasefire that has been in place since 6 September 1991 and he is determined to do everything possible to remove all obstacles to the resumption of the political process," Stéphane Dujarric, Spokesman for the UN Secretary-General said in a statement.
Over the years, more than 100,000 people from the area have become refugees due to the conflict, according to a Global Security report.