Hundreds of people, including governmental and religious authorities, gathered at the venue to observe the funeral mass. As the victims' remains came, the already tense chamber was filled with sobs.
Church officials condemned the massacre and demanded that the government do more to safeguard residents.
"I call on President Buhari and our leaders in the federal government or state government to wake up, sit up and act up to secure lives and properties all over Nigeria," said Catholic Bishop Emmanuel Badejo, one of the officiating clergymen. "How many more must die? Does life really have any value anymore with you?" Badejo added.
Governor Rotimi Akeredolu of Ondo State has committed to increase security.
"What has happened to us in Owo is indescribable, I'm short of words," he said. "We still have over 70 in the hospital, some have been discharged. I'm here before you to accept a failure of security, we have failed to defend these people."
Authorities blamed the Islamic State West African Province for the attack, which killed at least 40 worshippers and raised fears that the terrorist group is spreading from the north to other parts of Nigeria.
Armed gangs are increasing their attacks as the African country's national elections near. Outgoing President Buhari promised to increase security when he was elected seven years ago.
The Nigerian parliament has urged the government to declare a state of emergency in Ondo state. In addition, an armed security squad known as Amotekun in southwest Nigeria, backed by regional forces, has sworn to keep people safe and pursue the culprits of the church massacre.