Zanzibar's bishop said priests and other clergy in his diocese are terrified after a priest was murdered outside his parish church in what is seen by many as a terrorist attack.
"We are very afraid," Bishop Augustine Shao said, noting that clergy "were warned of attacks" before and after the Feb. 17 murder of 56-year-old Fr. Evaristus Mushi.
Mushi's car was followed by two men on motorcycles who blocked his way, shot and killed him, Shao said in a telephone interview Thursday from Zanzibar, a group of Indian Ocean islands that is part of Tanzania.
The Vatican's Fides news agency reported that a text message, received by bishops and priests in Tanzania after Mushi's death, said: "We thank our young men, trained in Somalia, for killing an infidel. Many more will die. We will burn homes and churches. We have not finished: at Easter, be prepared for disaster"; Signed "Muslim Renewal."
"We have given the warnings we have received to security" authorities in Zanzibar, Shao said, noting he was skeptical but hopeful that the perpetrators would be brought to justice.
"Many promises have been made, but they (the authorities) are very slow to make good on these promises," he said.
Tanzania President Jakaya Kikwete said in a statement he had directed the police force to use its full strength to conduct a speedy and thorough investigation into Mushi's murder.
The Tanzanian inspector general of police, Said Mwema, said the police "understand that these crimes are being propped up by some bad elements under the pretext of politics, religion or economic reasons, though no religion or political grouping supports violence in principle," reported Tanzania's Daily News.
About 30 percent of mainland Tanzanians are Christian, 35 percent are Muslim and 35 percent profess traditional African beliefs. In Zanzibar, more than 95 percent of residents are Muslim.
About two-thirds of Zanzibar's population of 1.2 million lives on the main island of Unguja, about 30 miles from Dar es Salaam, Tanzania's largest city and commercial hub.
A Protestant pastor in Zanzibar, Mathew Kachira, was killed Feb. 10, Fides reported.
Shao said another diocesan priest, Fr. Ambrose Mkenda, was shot and seriously wounded on Christmas Day and is still in the hospital.
Also, last November, a Muslim cleric had his face and chest injured in an acid attack.
More than five churches on the island were set alight in arson attacks last year.
This type of attack "is new to the country, and we are looking for reasons," Shao said, noting that the perpetrators "could be criminals using the cover of religion."
Another possibility is that advocates for Zanzibar's secession from the mainland are "using attacks on the church for political gain," Shao said.
"They feel that no one is listening to them, and it could be that, through these attacks on the church, they want to draw the world's attention to their cause," he said.
While "Christians and Muslims have been living peacefully together in Zanzibar for more than 200 years," Muslim extremists "have infiltrated the island and are said to be bribing unemployed youth to carry out their work," the bishop said.
Extreme poverty in the East African nation "makes people vulnerable to bribery," he said.
Tanzania is "a peaceful country and we walk as a nation," Shao said, noting that "the fact that we share a language -- Swahili -- has been a very uniting factor."
The church and its people in Zanzibar "are simple citizens, without a political agenda, so why are we being attacked to achieve political aims?" he said.
Zanzibar "is not a big place, and so this new violence can be brought under control if those in charge do their work properly," he said.
A Tanzanian government spokesman called Mushi's murder a "terrorist attack," according to Tanzania newspaper, The Citizen.
Bishop Robert Lynch of St. Petersburg, Fla., in whose diocese Mushi had worked, said in a blog the details of the priest's death "were astounding to me and crushing. This good priest whom the people of St. Benedict's Parish in Crystal River and Our Lady of Grace Parish in Beverly Hills came to know and love was murdered."
Lynch said Mushi was an "extremely kind, generous and genuinely holy priest" who "may well be a martyr for the faith."
Cardinal Polycarp Pengo of Dar es Salaam celebrated the funeral Mass on Wednesday for Mushi in Zanzibar.