Nigeria's military on Tuesday said it has arrested suspects in an attack on a church in June in which 40 people were killed.

Chief of Defence Staff General Leo Irabor told local media the suspects were apprehended during joint operations involving the armed forces, the Department of Security Services and police.

It was not immediately clear how many suspects were arrested.

Attackers stormed the St. Francis Catholic Church in the southwestern state of Ondo on June 5 and opened fire indiscriminately at the congregants.

Besides the 40 killed, more than 80 other people were wounded.