Tens of thousands of people rallied across Myanmar on Sunday to denounce last week's coup and demand the release of elected leader Aung San Suu Kyi, in the biggest protests since the 2007 Saffron Revolution that helped lead to democratic reforms.

On the second day of widespread protests, crowds in the biggest city, Yangon, sported red shirts, red flags, and red balloons, the colour of Suu Kyi’s National League for Democracy (NLD) party...