"To practice your faith and pray is a crime in America?" Omar Shahin asked.
Shahin was one of six imams who attended a North American Imams Federation conference in Bloomington, Minn., escorted off a flight to Phoenix, The Star Tribune of Minneapolis reported.
US Airways says it will investigate the matter and says passenger safety is paramount.
The imams deny they did anything that could be considered threatening. They were released without charges after being questioned for five hours by federal law enforcement officials.
US Airways still denied the men travel after their release, saying their tickets had been refunded and they could go through another airline, The Star Tribune said.
The imams bought six one-way tickets on Northwest Airlines and flew to Phoenix without incident.
The national Council on American-Islamic Relations called for a congressional hearing about ethnic and religious profiling at airports.