The terminally ill (who can still walk) and the very old are the best patriots to use for suicide attacks. These people are going to die very soon anyway, so it allows them one final chance to make a heroic sacrifice for their people. You could also use captured soldiers. You just drug them and outfit them with a suicide vest, then send them back to a group of their compatriots.
Another idea is to form a group of pseudo-sympathizers who 'welcome their liberators' with poisoned food and drink.