Anger at the military's heavy hand and land seizures rattles a year-old calm in the east, a rare success in a 25-year war.
While the military is making gains on the Tamil Tigers, it could become mired in guerrilla attacks.
Saturday's elections in an old Tamil Tiger stronghold offer the prospect of more autonomy and an end to civil war.
A rush-hour bomb blast killed dozens near Colombo, Friday. Earlier, the Army announced it had recaptured a key church.