Several thousand people rallied on Wednesday in Russia’s fourth-largest city as the showdown between authorities and activists protesting the plans to a build a new cathedral in a local park entered its third day. Thousands gathered in a riverside park in Yekaterinburg Wednesday evening. Some of them were on bicycles, more camped out on the grass while others were walking their dogs. As night fell, protesters turned on the light on their mobile phones and flashlights, chanting “We stand for the park!” Security measures for what has largely been a peaceful protest were heighted on the eve of the rally,...