MYANMAR police fired on protesters around the country yesterday in the bloodiest day of weeks of demonstrations against a military coup and at least 18 people were killed, the U.N. human rights office said. Police were out in force early and opened fire in different parts of the biggest city of Yangon after stun grenades, tear gas and shots in the air failed to break up crowds. Soldiers also reinforced police. Several wounded people were hauled away by fellow protesters, leaving bloody smears on pavements, media images showed. One man died after being brought to a hospital with a bullet…