Opelousas, Louisiana (CNN) As arson investigators worked to find out who has been setting Louisiana churches ablaze, the Rev. Dwight Brown slept in his church two nights last week, he said Wednesday.

"I was afraid my church was going to be targeted. My church is directly between two of the churches," he said. "I wasn't going to sit there and let it burn down. It's 130 years of history. I couldn't take that chance."

Brown asked that CNN not divulge the name of his church, for fear that it could become a target, but it sits near two of the three churches that burned in recent weeks in St. Landry Parish, about an hour's drive west of Baton Rouge.

Firefighters respond to a fire at Mt. Pleasant Baptist Church in Opelousas on Thursday.

Police say three black churches were intentionally torched over a 10-day span: St. Mary Baptist Church in Port Barre on March 26, Greater Union Baptist Church in Opelousas on April 2 and Mount Pleasant Baptist Church on Thursday.

Officials are also investigating a fourth, smaller fire on March 31 at the predominantly white Vivian United Pentecostal Church in Caddo Parish, more than 200 miles north of St. Landry. The blaze was intentionally set, officials said.

Read More