Algeria has accused Morocco of killing three of its nationals on a desert highway, as tensions escalate between the neighbours over contested Western Sahara.
"Three Algerian nationals were cowardly murdered after their trucks were 'barbarically bombarded' on the road linking Nouakchott to Ouargla", Algeria's presidency said, quoted by APS.
The trucks were travelling from the Mauritanian capital Nouakchott toward the Algerian city of Ouargla as part of "normal commercial exchanges" when they were targeted.
"Several factors point to Morocco's occupation forces in Western Sahara as having committed with sophisticated weaponry this cowardly murder. This brutal aggressiveness is characteristic of a known policy of territorial expansion and terror," the statement went on.
The source added that the killings would "not go unpunished".
The reported killings took place on Monday, but few details had emerged and there had been no immediate response from Morocco's government.
Mauritania’s army issued a statement denying it targeted any Algerian trucks.
Western Sahara is 80 per cent controlled by Morocco, which sees the former Spanish colony, rich in phosphates and adjacent to rich fishing waters of the Atlantic, as an integral part of its own territory.
Tensions between Algeria and Morocco have been exceptionally high in recent months.
Algeria has long supported the Polisario Front, which seeks full independence and has demanded a referendum as provided for in a 1991 ceasefire deal.
However, the Polisario in November declared the truce "null and void" after Moroccan forces broke up a blockade of a highway into Mauritania, which the independence movement said was built in violation of the ceasefire.
The two North African countries broke off diplomatic ties in August citing "hostile actions".
On Sunday, energy-rich Algeria shut off a gas pipeline that fuels Morocco and Spain, heightening tensions.
UN Secretary-General Antonio Guterres has warned that the situation in Western Sahara has "significantly deteriorated" over the past year.
On Friday, the UN Security Council called for renewed peace talks, in a resolution Algeria slammed as "fundamentally unbalanced".