Belgian police clashed with hundreds of demonstrators outside the European Union’s headquarters in Brussels on Thursday night, breaking up a protest against Israel’s interception of the Gaza-bound Global Sumud Flotilla and the arrests of activists aboard. In Barcelona, demonstrators blocked traffic and vandalized shops and restaurants, while marches spread as far as Argentina, Colombia, and Mexico. The violence in Brussels followed Israel’s arrest of hundreds of activists and seizure of dozens of ships from the Global Sumud Flotilla while it was still in international waters. “The interception of the flotilla’s ships and the seizure of humanitarian aid constitute a blatant violation of international law,” Hassan’s office said. The 500-person flotilla, which aimed to break Israel’s blockade of the Strip imposed since March 2, saw roughly 443 volunteers arrested.