NAIROBI, Kenya — An American missionary who ran a conservative evangelical church and radio station in Rwanda was arrested in Kigali, the country’s capital, on Monday before he could hold a news conference to denounce the government for clamping down on churches like his.

The Rev. Gregg Schoof is one of several outspoken evangelical pastors who have criticized the Rwandan government for allowing access to abortion and birth control, and for teaching evolution. He was detained for attempting to hold a news conference without permission said Modeste Mbabazi, spokesman for the Rwanda Investigation Bureau.

Mr. Schoof moved his family from Indiana to Rwanda 16 years ago, nearly a decade after the genocide that killed as many as one million people. He established a Baptist church and Amazing Grace Christian Radio. But the government of President Paul Kagame last year revoked his station’s license and shut down his church, and recently refused to renew visas for Mr. Schoof and his family, Mr. Schoof said.

“I did not come here to fight the government. I came to preach the Gospel,” Mr. Schoof said in a statement he brought to what he had billed as a final news conference. “But this government has taken a stand against God with its heathen practices.”