The European Union will ask major US technology companies including Facebook, Google and Twitter to help tackle online extremism at a meeting on Wednesday, officials said. The dinner meeting in Luxembourg comes amid rising concerns about the use of the Internet to radicalise young European Muslims who have travelled to fight in Syria and Iraq. Interior ministers from the 28 EU countries and officials from the European Commission will meet representatives from Internet search giant Google, social media leaders Facebook and Twitter, and software pioneer Microsoft, a commission spokesman told AFP.