Every Tuesday, the moss-covered redbrick courthouse in Tharrawaddy erupts into activity for a weekly ritual: the mass trial of student protesters.

Under heavy guard at a session in late August, 81 students faced charges related to protests that were crushed by baton-wielding police in March.

They are among a growing number of people caught in a crackdown on dissent as Myanmar heads toward a historic election in November, when the military-backed ruling party will compete with the ascendant National League for Democracy (NLD) party of Nobel laureate Aung San Suu Kyi in the first free national vote in 25 years.