Opponents of Myanmar’s military coup sustained mass protests for an eighth straight day on Saturday as continuing arrests of junta critics added to anger over the detention of elected leader Aung San Suu Kyi. Thousands assembled in the business hub, Yangon, while protesters took to the streets of the capital Naypyitaw, the second city Mandalay and other towns a day after the biggest protests so far in the Southeast Asian country. “Stop kidnapping at night,” was among the signs held up by protesters in Yangon in response to arrest raids in recent days. The United Nations human rights office said on Friday more than 350 people, including officials, activists and monks, have been arrested in Myanmar since the Feb. 1 coup, including some who face criminal charges on “dubious grounds”. Anger in...