Tosin Ikuemolo, 22, and six other prisoners had escaped after they dug the pipe of a toilet, with help of a Hausa man among them.
The international organisation urged the government at all levels to redouble efforts to protect children against violence.
At least 50 church attendees, including under-age children between the ages of 8, 10 and 12 years old, were kept in an “underground” facility of the church.
Kidnapping for ransom by armed bandits have since become a nightmare engulfing the people of Akoko, in the northern senatorial district of Ondo state.
The criminals specialise in the theft of generating engines and taking them to Owode Onirin, in Kosofe LGA, Lagos, to sell.
“I can not confirm anything like that. There is no story like that in the state,” the Ondo police spokesperson said.
This came barely three days after the massacre of worshippers at St. Francis Catholic Church at Iwa-luwa in Owo.
The police also failed to arrest any suspects in the attack, which left about 50 killed and dozens wounded on Sunday morning.
A witness told journalists that the victims were travelling when the abductors accosted and dragged them into the bush to an unknown destination.
The victims were rescued on April 22, at about 6:30 p.m., when the Police Rapid Respond Squad were on a routine check of the highway.