Complex sentence: A "state of precations" was imposed, which decreed that local government kept surveillance on suspected troublemakers and, if necessary, order curfew, while special permits were required to travel through the town.
Split into simpler sentences: A "state of precations" was enacted, which decreed that the local government maintained surveillance over suspected troublemakers and, if necessary, order a curfew. Special permits were required to travel through the town.