French police officers used tear gas to disperse a crowd of hundreds of demonstrators at the Place de la République on Sunday. They also detained about 100 people who had projectiles or other suspicious objects, The Associated Press reports. The demonstrators were protesting to call on world leaders for a global commitment to curbing climate change, one day before the start of a landmark summit in Paris. The Paris police chief said the demonstrators violated the ban on protests being enforced under France's ongoing state of emergency, which authorities put in place after the Nov.