A flag parade marked the opening of the World Robot Olympiad (WRO) 2015 at the Al Shaqab Indoor Arena in Doha yesterday. The three-day event is being held under the patronage of HE the Prime Minister and Interior Minister Sheikh Abdullah bin Nasser bin Khalifa al-Thani. More than 3,000 participants from 55 countries are competing in four different categories of robotics challenges. The WRO is hosted by the College of the North Atlantic - Qatar, sponsored by Maersk Oil Qatar and endorsed by the Supreme Education Council and Qatar Petroleum. This year’s WRO is one of the largest in the competition’s 12-year history.