PARIS/LE HAVRE (Reuters) - A Saudi vessel that had been due to load weapons at a northern French port on Friday set sail without them and headed for Spain, a day after a rights group tried to block the cargo on humanitarian grounds.

A French patrol boat sails next to the Bahri-Yanbu, a Saudi Arabian cargo ship, that waits to enter in the port of Le Havre, as human rights groups try to block the loading of weapons onto the vessel, France, May 10, 2019. REUTERS/Benoit Tessier

French rights group ACAT argued in a legal challenge on Thursday that the consignment contravened a U.N. treaty because the arms might be used against civilians in Yemen.

A French judge threw out that legal challenge but the Bahri-Yanbu set course for Santander shortly after minus the weapons, officials said and ship-tracking data showed.

The saga is an embarrassment for President Emmanuel Macron, who on Thursday defended arms sales to Saudi Arabia.

Riyadh leads the pro-government military coalition in the four-year civil war that has devastated Yemen, killed tens of thousands and left much of the population on the brink of famine.

Macron said on Thursday Riyadh, which he called a key ally in the fight against terrorism, had assured him the weapons the ship was to load were not to be used against civilians.

An official working for Jean-Paul Lecoq, the opposition Communist member of parliament for port city Le Havre, confirmed the vessel had left without the consignment.

“This is a lesson for the executive,” he told Reuters. “It can no longer give bland statements saying ‘do not worry, we have guarantees’. That no longer works.”

European powers are split over arms sales to Saudi Arabia, with France and Britain lobbying against German efforts to toughen the way they are regulated.

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The Bahri-Yanbu had been at anchor 25 kilometers (15 miles) off Le Havre since Wednesday evening, already carrying a separate consignment of arms loaded in Antwerp.

WAR CRIMES ALLEGATIONS

France’s defense ministry referred questions about the consignment to the foreign ministry, which referred Reuters back to the defense ministry. Neither the prime minister’s office, which approves arms’ sales, nor the presidency responded.

A Saudi embassy spokesman could not immediately comment.

The move by ACAT came after online investigative site Disclose published leaked military intelligence showing weapons sold by France to Saudi Arabia, including tanks and laser-guided missile systems, were being used against civilians in Yemen.

Finance Minister Bruno Le Maire said on Friday that Paris adhered to rules related to arms sales,

France is one of Saudi Arabia’s main arms’ suppliers, but has also faced increasing domestic pressure to review that trade relationship as the human cost of Yemen’s war has risen.

ACAT had argued that the transfer contravened the U.N. Arms Trade Treaty, which says one country cannot authorize the transfer of weapons if it knows at the time that those weapons could be used to commit war crimes or target civilians.

U.N. officials have said all sides in the Yemeni conflict may have committed war crimes.

The government declined to give details of the arms order, which Disclose had said included eight Caesar howitzer cannons.