Foreign Minister Didier Reynders told RTBF: "I think it would be good to suspend arms deliveries to Saudi Arabia" if it were shown they had been used "in an ongoing conflict, such as in Yemen," in which case he said the regional Walloonian government "must" take that decision.

Belgium's constitution places responsibility for such decisions on the producer region, in this case Wallonia, which owns the arms manufacturer FN Herstal.

Regional president Willy Borsus told RTBF it "could go as far as suspending existing arms export licenses" if conditions under which they were granted had been violated.

Belgian newspaper Le Soir said Wednesday an investigation showed Ryad had used Belgian arms and technology in operations against Huthi rebels in Yemen, where more than four years of fighting has killed tens of thousands of people, relief agencies say.

The fighting has triggered what the United Nations describes as the world's worst humanitarian crisis, with 3.3 million people still displaced and 24.1 million -- more than two-thirds of the population -- in need of aid.

The issue of Saudi arms sales divides European governments, with French President Emmanuel Macron defending such sales Thursday as part of "the fight against terrorism."

Germany however suspended arms sales to Riyad after the killing last year of Saudi dissident Jamal Khashoggi in Istanbul, posing a problem for European partners because it can affect weapons produced jointly.

A diplomatic source said the issue would be discussed Monday by EU foreign ministers in Brussels, because Saudi Arabia is also backing Libyan rebel leader Khalifa Haftar in his bid to overthrow a government in Tripoli that has EU backing.

The EU has committed to enforcing a UN arms embargo in Libya.