In an act of defiance against Saudi Arabia's brutal assault on Yemen—which is being carried out with the support of the United States and European nations—Italian union workers on Monday refused to load a Saudi vessel reportedly filled with weapons that could be used to fuel the world's worst humanitarian crisis.

"We will not be complicit in what is happening in Yemen," union leaders said in a statement.

According to Reuters, dockworkers attempted to have the Saudi ship—officially called the the Bahri Yanbu—barred from entering the Port of Genoa.

When that effort failed, Reuters reported, "workers refused to load two generators aboard the boat, saying that although they were registered for civilian use, they could be instead directed to the Yemen war effort."

As Amnesty International noted in a statement last week, the Bahri Yanbu has been "bouncing off European ports like a pinball," loading up with weapons that rights groups warn will be used to massacre civilians in Yemen.

Earlier this month, the Bahri Yanbu left a French port without its cargo amid protests from Christian Action for the Abolition of Torture (ACAT) and other human rights organizations. The vessel then proceeded to Spain, where it successfully "took on cargo contracted from private companies," according to Al Jazeera.

"No EU state should be making the deadly decision to authorize the transfer or transit of arms to a conflict where there is a clear risk they will be used in war crimes and other serious violations of international law," Ara Marcen Naval, deputy director for arms control and human rights at Amnesty International, said in a statement.

"The Bahri Yanbu's voyage reminds us that states prefer to allow the lucrative global arms trade to continue to operate behind a veil of secrecy," Naval concluded. "But this veil is not impenetrable, and Amnesty International and its partners will continue to closely monitor developments and denounce states for flouting their international legal obligations.”