Tanzanian police have arrested 15 people, including suspects with ties to terror groups, believed to be responsible for a series of acid attacks.
According to the police commissioner, some of the suspects have links to al Qaeda and Somali militant group al-Shabab.
Tuesday's arrest follows an acid attack on a Catholic priest in a crowded part of town Friday afternoon.
Rev. Joseph Anselmo Mwagambwa is being treated at a Tanzanian hospital following an acid attack in Zanzibar.
Officers say Mwagambwa's face, chest, thighs and legs were badly injured.
This was the fifth acid attack in Zanzibar since November.
Just last month, an assailant threw acid in the faces of two young British women doing volunteer work.