Confirming a report in the newspaper L'Echo, Wallonia said Minister-President Elio di Rupo had "the Yemen drama" in mind when refusing an export licence to the Saudi air force.

In a letter seen by AFP, it added "the minister-president refuses all licences for the Saudi defence ministry."

Saudi Arabia's Royal Guard and National Guard, which French-speaking Wallonia sees as less implicated in the Yemeni conflict, will continue to receive Belgian weapons and ammunition.

In Belgium, licences for arms sales are issued by regional governments, and human rights groups have been lobbying Wallonia to halt shipments to the Saudis.

Saudi Arabia intervened in the almost five-year civil war in its southern neighbour to support the government side, but the conflict has claimed tens of thousands of civilian lives.

The kingdom is one of the world's biggest arms purchasers, spending billions with the United States and the United Kingdom in particular.

Riyadh depends less on Belgium arms, but is nevertheless Wallonia's number one customer, accounting for 225 million euros ($247 million) in a 950 million euro industry in 2018.

FN Herstal, which makes rifles and machine guns, and John Cockerill (CMI), which specialises in gun turrets for armoured vehicles, employ 4,400 Belgians between them.

The regional government is FN Herstal's sole shareholder.

Wallonia's announcement came as a coalition of human rights groups denounced the imminent arrival in France of a cargo ship said to be picking up European weapons for the Saudis.