YANGON, March 15 (CNA) - Myanmar's military government late on Sunday (Mar 14) imposed martial law in two densely populated Yangon townships after at least 18 protesters were killed in one of the deadliest days since the Feb 1 coup.

Sunday's violence brings the number of people killed in mass protests since the military wrenched civilian leader Aung San Suu Kyi from power to around 100, though activists and rights groups believe it could be higher.

The junta has repeatedly justified its power grab by alleging widespread electoral fraud in November's elections, which Aung San Suu Kyi's National League for Democracy (NLD) party won by a landslide.

State-run media announced late Sunday that Yangon's massive Hlaing Tharyar township and the neighbouring Shwepyitha township will be placed under martial law.