Air travel across Europe was thrown into chaos on Wednesday as air traffic controllers went on strike against an EU plan to put the continent's air space under international controls. Thousands of passengers had their travel plans disrupted as controllers in France, Italy, Portugal, Greece and Hungary walked out. Hundreds of flights were cancelled or delayed. France was the worst hit. Normally bustling airports stood empty as passengers heeded warnings to stay away, and there were reports of long queues at train stations as people looked for alternative transport.