A priest was attacked with acid on the east African island of Zanzibar in the third such unprovoked assault in two months, and remained hospitalized Saturday, the cleric told CNN.

The Rev. Joseph Anselmo Mwagambwa said he was attacked Friday afternoon while coming out of an internet cafe in Mlandenge, a community in the city of Zanzibar.

He was being treated in a hospital in the Tanzanian mainland town of Dar es Salaam.

Police are still investigating, and no arrests have been made.

Last month, two British women, both 18, were walking unaccompanied on a street when acid was thrown on their faces, chests and hands by two men on a motorcycle in Zanzibar, officials said.

Katie Gee and Kirstie Trup were attacked in Stone Town, the island’s historic center, and had been working as volunteer teachers on the island, according to the firm i-to-i Travel. Stone Town is a UNESCO World Heritage Site popular with tourists.

The attack against the two women came as Islamist extremism is rising in the area. The government said it would consider regulating the purchase of acid and other related products, and warned that such attacks could seriously damage the island’s tourism industry.

In another incident in July, a businessman of Arab origin who had built a mall close to the American Embassy in Dar es Salaam was also injured in an acid attack, Tanzanian media reported.

Zanzibar is a semi-autonomous part of Tanzania. According to the CIA World Factbook, the population of Zanzibar is 99% Muslim, while the residents of mainland Tanzania are split roughly evenly among Christian, Muslim and indigenous beliefs.

Read More: CNN