Algeria said Wednesday three truck drivers had been killed in a bombing as they drove from Mauritania, an attack Algiers blamed on neighbouring Morocco, the official APS news agency said.
"Three Algerians were assassinated... in a barbaric strike on their trucks," Algeria's presidency said in a statement, quoted by APS.
It reported they had been travelling between the Mauritanian capital Nouakchott and the Algerian city of Ouargla.
"Several factors indicate that the Moroccan occupation forces in the Western Sahara carried out this cowardly assassination with a sophisticated weapon," the statement added.
The Western Sahara is 80 percent controlled by Morocco, which sees the former Spanish colony as an integral part of its own territory.
But its regional arch-rival Algeria has long hosted and supported the Polisario Front, which seeks full independence there.
The reported killings took place on Monday, but few details had emerged, and there had been no immediate comment from Rabat or Algiers.
The Algerian statement did not specify the exact location where the bombardment took place.
But Akram Kharief, editor of Algerian website Mena Defense, said that "the Algerian truckers were killed in Bir Lahlou", on a highway through the part of the Western Sahara controlled by the Polisario Front.
The Polisario in November declared a three-decade ceasefire "null and void" after Moroccan forces broke up a blockade of a highway into Mauritania that the independence movement said was built in violation of a 1991 truce.
In August, Algeria broke off diplomatic ties with Morocco citing "hostile actions" -- charges Rabat dismissed.
On Friday, the United Nations Security Council called for renewed peace talks, in a resolution Algeria slammed as "fundamentally unbalanced".
UN Secretary-General Antonio Guterres warned that the situation in Western Sahara had "significantly deteriorated" over the past year.
Former US president Donald Trump broke with long-held diplomatic norms last year to recognise Morocco's claim to the territory as part of a quid pro quo for Rabat's normalisation of ties with Israel.
His successor Joe Biden's administration has not yet confirmed or rescinded the decision.