YANGON, Burma—As enthusiastic crowds of tens of thousands marched through the streets of Burma (also known as Myanmar)’s biggest city on Sunday to protest last week’s coup ousting Aung San Suu Kyi’s elected government, their spirits were lifted by the return of internet services that had been blocked a day earlier. Separate protests that began in various parts of Yangon converged at Sule Pagoda, situated in the center of a roundabout in the city’s downtown area. Protesters chanted “Long live Mother Suu” and “Down with military dictatorship.” Protesters in other parts of the country echoed their calls. Authorities had cut access to the internet as the protests grew Saturday, fanning fears of a complete information blackout. On Sunday afternoon, however, internet users in Yangon reported that data access on their mobile phones had suddenly been restored. The demonstrators are seeking to roll back last Monday’s seizure of power by the …