FILE PHOTO - Belgium's Asylum and Migration State Secretary Theo Francken visits a military barrack used as an accommodation centre for refugees in Namur, Belgium, September 24, 2015. REUTERS/Francois Lenoir

BRUSSELS (Reuters) - Belgium’s migration minister on Tuesday attacked aid groups for saving drowning migrants in the Mediterranean, saying they were only causing more death by doing so, earning himself a rebuke from his own prime minister.

Thousands of migrants have drowned on their journey across the central Mediterranean in the last couple of years, as millions make the journey to escape poverty and war.

Human traffickers often prepare ramshackle boats for the crossing that are not designed to last the entire trip to Europe’s southern shores, the UN refugee agency UNHCR has said.

Doctors Without Borders, best known by its French acronym MSF, operates two boats off the Libyan coast to assist migrants in distress in an operation coordinated by the Italian coast guard.

Theo Francken, who recently made headlines during a court battle to refuse humanitarian visas to a family of Syrian refugees from besieged Aleppo, criticised MSF for this operation on Twitter.

“By saving them you are indirectly causing only more death,” Francken said.

“They have to stay away. They are trafficking humans. It has nothing to do with refugees, this is illegal migration,” he added.

MSF, which says on its website that it has saved some 24,000 migrants from drowning, said it regretted that a member of the Belgian government criticised it for saving lives.

Belgian Prime Minister Charles Michel called on Francken to “show more nuance in his communication” and “respect humanitarian work”, Belgian broadcaster VRT reported.