Parish priest Father Michael King was inside the church preparing to conduct the marriage ceremony when the shooting happened outside.
Fr King told local radio that he nevertheless went ahead with the ceremony.
"I went on ahead with the wedding, I could do nothing else because they were anxious to get this girl married," he said.
"So I went on ahead and did Mass and did the wedding."
A man in his sixties who was shot, was flown to hospital in a police helicopter but later died from his injuries. Another man was injured while a third man was stabbed.