In "The Crucible", how and by whom are the other villagers accused of witchcraft?

In the beginning of Act One of “The Crucible” it is revealed that the young, teenage girls of Salem had been in the forest the night before the incidents of this act have occurred.   While in the forest they were suspected of conjuring up spirits and Abigail actually drank blood which she though to be a charm that would kill John Proctor’s wife.  After this occurs, the girls are afraid that they are going to get into trouble when Betty Parris and Ruth Putnam are found in a trance and can not wake up.  Therefore, the girls, in an effort to protect themselves and save themselves from being called witches begin to accuse people of the village.  This is how the witchcraft accusations begin and who begins the accusations.