Algiers - The Polisario Front, which seeks independence for Moroccan-controlled Western Sahara, said on Wednesday it had arrested 19 drug traffickers from Morocco and accused Rabat of complicity.
Polisario forces on July 16 arrested "19 Moroccan drug traffickers who had crossed the wall", Polisario member Mhamed Khadad said.
He was referring to a 2 700km sand barrier marking out Moroccan-controlled and Polisario-held territory in the disputed region.
He said the smugglers had crossed the barrier "with the complicity of (Moroccan) soldiers" in Guelta Zemmour, 30km from the Western Sahara's border with Mauritania.
Moroccan authorities did not immediately respond to the accusations.
Morocco fought the Polisario from 1975 until a ceasefire in 1991, enforced by a United Nations peacekeeping force.
Rabat insists the Western Sahara is an integral part of its kingdom, despite UN resolutions calling for a referendum on self-administration.
The Algeria-backed Polisario Front controls a band of the former Spanish colony, east of the Moroccan-built security wall snaking through the desert.
Khadad said the Polisario had intercepted tons of drugs from Morocco in 2016 and 2017, accusing Moroccan authorities of "complicity" in the trade.
The United Nations anti-drugs agency says Morocco is the world's largest producer of hashish and one of the main exporters of cannabis resin, mostly destined for Europe.
The International Narcotics Control Board (INCB) said in 2015 that production was falling due to efforts by Moroccan authorities.