KAMPALA, Uganda — A Pentecostal preacher who has converted thousands of Muslims to Christianity was disfigured when men shouting “God is great” in Arabic threw acid in his face in a Christmas Eve attack that has stoked religious tensions here.
The victim, Umar Mulinde, is a Muslim convert to Christianity and now a vocal critic of Islam. He is also a key figure in opposing the establishment of Islamic civil courts in this majority Christian country.
Christians say the attack on Mr. Mulinde is symbolic of the government’s failure to protect Christians from Muslim extremists, even in a country whose population is 85 percent Christian. They say Muslims refuse to accept the concept of religious freedom, especially the right to choose how one worships.
Mainstream Muslims say they practice a tolerant version of Islam and that violent thugs like the ones who attacked Mr. Mulinde do not represent them.
Muslims make up 12 percent of the population of 35 million in this East African nation.
“The main point of contention between Muslims and Christians in Uganda is that Muslims are yet to embrace the reality of freedom of worship or coexistence, but Muslims always think that any person who doesn’t believe like them is an enemy who deserves to be killed,” said Mr. Mulinde’s wife, Evelyn, also a former Muslim.
Bishop David Kiganda of the National Fellowship of Born Again Pentecostal Churches called the attack on Mr. Mulinde a “terrorism act that the government should take seriously.”
Nsereko Mutumba, a spokesman for the Uganda Muslim Supreme Council in Kampala, said some Christian leaders are using the attack on Mr. Mulinde as an opportunity to promote themselves as defenders of Christianity.
He insisted that most Muslims in Uganda are tolerant of religious conversions, unlike Muslims in many Islamic countries where converts face death sentences.
“Muslims here don’t care what religion one decides to be,” Mr. Mutumba said.
Ssekito Abdulhakim, general secretary of the Makerere University Muslim Students Association, said Muslim-Christian tensions are rising mainly because both Muslims and Christians have become more active in conversion efforts.
Muslim and Christian speakers often hold public debates and try to convert members of the audience. Each speaker will claim his religion is the one true word of God.
Joshua Kitakule, secretary-general of the Inter-Religious Council of Uganda, called those forums divisive.
“These debates are not respectful and healthy. They’re built on saying one is right, the other is wrong. That offends,” he said.
“Preach your gospel as is, and if people like it, they will convert. But there’s no need to disrespect the other.”
Mr. Mulinde, with extensive knowledge of both the Koran and the Bible, was active and persuasive in many of those debates. He has received death threats and narrowly escaped attempts on his life several times from Muslims who do not share Uganda’s reputation for tolerance.
“I have been receiving several threats for a long time, and this last one is the worst of all,” he told Uganda’s Compass news service in a hospital interview shortly after the attack.
“I have bore the marks of Jesus,” he said.
Mr. Mulinde, a 38-year-old father of six, described the attacker who threw acid onto his face as a man pretending to be a Christian. The attacker approached Mr. Mulinde after the Christmas Eve service at his Gospel Life Church International, about 10 miles outside of Kampala.
“I heard him say in a loud voice, ‘Pastor, pastor,’ and as I made a turn and looked at him, he poured the liquid onto my face,” Mr. Mulinde said.
Mr. Mulinde said the man fled, shouting, “Allah akbar,” or “God is great.”
The attack disfigured the right side of his face and left him blind in his right eye.
“I was born into a Muslim family and, although I decided to become a Christian, I have been financially assisting many Muslims, as well as my relatives who are Muslims,” he told Compass.
“I have been conducting a peaceful evangelism campaign.”
Police suspect the attack might have been the result of a dispute between Mr. Mulinde and the family that sold him the land where he built his church. They arrested one suspect but released him after he established an alibi. No other arrests have been made.
Religious conversions also have gone from Christian to Muslim, especially in once celebrated case.
Uganda’s most popular musician, Jose Chameleone, converted to Islam in August and changed his name to Gaddafi before converting back to Catholicism amid an outcry from his family and fans.
Many suspect the conversion was a publicity stunt to promote a new album, but he managed to offend followers of both faiths.
So far, Muslims and Christians here have avoided widespread violence like that in Nigeria, where the Islamist group Boko Haram killed 35 people on Christmas Day.
Advocates of religious freedom emphasize the need for vigilance.
The central Buganda Kingdom underwent an outbreak of bloody Muslim-Christian conflicts beginning the 1880s, and suspicions have lingered.
After independence, dictator Idi Amin converted to Islam, and Muslims suffered revenge attacks after his ouster in 1979.
Mr. Mulinde grabbed attention more than 10 years ago by defying an Islamic dietary law against eating pork. After converting to Christianity, he reportedly donned a Muslim skullcap, slaughtered a pig and ate it with other converts.
Before the acid attack, Mr. Muline led a campaign to block the Ugandan legislature from allowing Muslims to bring legal action under Islamic law in civil courts.
The courts would have had jurisdictions over marriage, divorce and inheritance matters.