Myanmar's military has imposed martial law across more districts around the country following the deadliest day of protests since February's coup, BBC reported today. About 50 people were reported killed when troops and police opened fire on protesters in various areas on Sunday. Most deaths were in Yangon. The violence came a day before ousted civilian leader Aung San Suu Kyi was due to appear in court. On Monday, her virtual hearing was adjourned due to internet problems. Pro-democracy protesters are demanding the release of Ms Suu Kyi, the head of the National League for Democracy (NLD) which saw a landslide victory in elections last November. She has been held at an unknown location since the 1 February coup. She is due to face a slew of charges her supporters say are fabricated. The military detained most of the NLD leadership after the coup, alleging voter fraud. No proof has been provided. The military initially declared martial law in two districts of Yangon (Rangoon), the country's largest city, on Sunday after Chinese businesses were attacked. Martial law was imposed in several other areas of Yangon and Mandalay on Monday. Protesters there can now be tried in military courts. Protesters believe China is giving support to the military in Myanmar (also called Burma) but it is unclear who was behind the weekend attacks.