The British government’s arms sales to Saudi Arabia have been declared unlawful by the U.K.’s court of appeal, The Guardian reports. Judges ruled in favor of an activist group that accused the government of going ahead with arms sales when there was a clear risk that they could be used in breaches of international humanitarian law in Yemen. One judge explained the ruling doesn’t mean that arms sales must be immediately suspended, but went on to say the government “must reconsider the matter” and estimate future risks of arms being used in Yemen. The U.K. has reportedly sold billions worth of arms to Saudi Arabia since the civil war in Yemen began in early 2015. Andrew Smith of Campaign Against Arms Trade, which brought the challenge, said: “The bombing has created the worst humanitarian crisis in the world. U.K. arms companies have profited every step of the way. The arms sales must stop immediately.”