Muslims came from other parts of France to be present for the service shared with Christians.
The killing on Tuesday of the 85-year-old Rev. Jacques Hamel as he celebrated morning Mass sent shockwaves around France, and deeply touched many among the nation's 5 million Muslims.
The Islamic State group claimed responsibility for the attack, as well as the attack in Nice, where 84 people were killed by a man who plowed his truck down a seaside promenade on Bastille Day.
"You have the wrong civilization because you are not a part of civilization. You have the wrong humanity because you are not a part of humanity," said Abdelatif Hmitou. "You have the wrong idea about us (Muslims) and we won't forgive you for this."
"How," he asked, addressing the extremists, "may the idea reach your mind that we might loathe those who helped us ...