RIO DE JANEIRO - Waters polluted by sewage off the coast of Rio remain a concern for organisers of the 2016 Olympics, but the International Olympic Committee insisted Friday that the sea will be safe for competition. Guanabara Bay, which will host the sailing at the Games, has caused consternation amongst some athletes with the water quality condemned as "disgusting" by one sailor. IOC co-ordination commission chair Nawal el Moutawakel noted on a sixth visit Friday that authorities have pledged to deliver a huge increase in sewage treatment by 2015. "There will be a seven-fold increase in treated sewage around the Guanabara Bay by 2015," she said, with sailing test events slated for August. Environmental officials said late last year that more than two thirds of sewage goes untreated in the Bay. –AFP