LONDON — In another sign that religious tensions are on the rise in Zanzibar, a Roman Catholic priest was burned in an acid attack on Friday.

The attack was the latest aimed at Christian clergy members and churches in the last year on the Tanzanian island, which has a Muslim majority.

It also came a month after two British teenage girls volunteering at a nursery school had acid thrown at them in Stone Town, the old part of Zanzibar City, and had to be flown back to Britain for skin grafts.

Mkadam Khamis, the deputy police commissioner for Zanzibar, said that by midnight no arrests had been made in the attack on the priest, the Rev. Joseph Mwang’amba, who was hospitalized after the attack.

News reports said that his attackers had waited for Father Mwang’amba as he was leaving an Internet cafe in the Mlandege area of the island, a popular tourist destination about 20 miles off the coast of the mainland.

“Still we don’t know who did this,” Mr. Khamis said in a telephone interview.

Conservative Muslims and Western visitors have long coexisted peacefully on Zanzibar, which welcomes some 200,000 tourists a year.

The attack on Friday was the third on a Christian clergy member on the island in the last year. In February, a Catholic priest was shot to death, and last year, another priest was shot and wounded. There have also been several arson attacks on Catholic churches.

Last November, a moderate Muslim cleric suffered burns from an acid attack.

The cleric, Sheik Fadhil Soraga, has blamed an Islamic group for the attacks on himself and on the two British girls. The group, which calls itself Uamsho, Swahili for “Awakening,” has said it wants Zanzibar to split from mainland Tanzania and force strict dress codes on foreign visitors. It also wants to ban alcohol outside private hotels.

So far, Mr. Khamis said, there is no evidence linking Uamsho to the attack on the teenagers or the Muslim cleric.