More than 20 children have vanished in the past few months, with their bodies found mutilated.
But one suspected killer was caught after he tried to attack two boys while they were fetching water from a well in in Yopougon, a suburb of Abidjan, on January 25.
Those gathered around the well watched in horror as Cedric, 14, and Souleymane, 10, were attacked by Drissa Coulibaly with a machete.
Souleymane was in shock, but he survived, unlike many victims of a wave of child murders in the Ivory Coast.
He said: 'The man came out with a machete. I fell down. He started to hack at me.'
The would-be killer went after Souleymane, then Cedric, before a soldier from a nearby base saw what was happening and chased the man away.
'I thought he had come to collect water, said Cedric. 'But he pulled out a machete. He tried to cut me up.'
As word spread, soldiers from the nearby base quickly fanned out and tracked down the attacker.
Once in police custody, he reportedly confessed to at least three murders.
Giving his name as Drissa Coulibaly, the suspect wore a red and white robe, filthy after months of living on the street.
He calmly told police that God had told him 'to cut off children's heads ... and then I would be made king.'
'God told me to do this. God told me to cut off children's heads and bring them to him and then I would be made king,' Coulibaby, 38, told AFP from custody.
'I told him that I didn't want to do this but he insisted,' he added.
His goal was to win his 'swords' of royalty, and he said he communicated with God by way of 'angels' in the shape of crows.
'Either he is very intelligent (and pretending to be mad) or he is very crazy,' one investigator said.
Cedric's mother, market seller Daniele Kone, was present when the attacker was questioned by troops.
'He's a very confident man. Not a madman,' she said. 'He is used to doing this.'
She told AFP that the suspect 'said he had already killed three children' for Internet clients known as 'browsers', a charge Coulibaly has since denied.
Browsers are the term used for delinquents who specialise in Internet scams and are widely regarded as behind the child murders, though proof is scanty.
Father Norbert Abekan, a charismatic Abidjan preacher, charged in an article last week that some browsers sought 'human sacrifices the better to swindle'.
'Fortunately, his machete was not well sharpened,' Corporal Habib Tito said after the search. 'He was determined to get the two children.
'Had it not been for the presence of one of our men, the smallest boy would be dead,' he added.
At least 20 children have not been as lucky as Souleymane and Cedric.
In the last two to three months, police opened 25 unexplained cases of child kidnappings, followed by murders, across the country.
First Lady Dominique Ouattara spoke out Tuesday against 'horrible and inhuman acts that nothing can justify'.
'It isn't right that parents should grow anxious each time their children go out of the front door of their houses,' she said.
Police called the murder toll extremely high, saying it is 'a real and unusual phenomenon', which has shocked Ivorians and spread fears that youngsters have become victims of ritual sacrifices.
Brindou M'Bia, the director general of national police, has said most bodies have been found 'mutilated, with their genital parts missing, or decapitated'.
'We know the typology of ritual crimes very well,' Interior Minister Hamed Bakayoko added.
'People are led to believe that through these crimes, they can gain power or money.'
He said 1,500 police and troops were being mobilised 'to patrol the areas with a high crime rate'.
The spate of child killings has prompted some hysterical responses, from warnings posted on Facebook to alarmist text messages. Kidnappings are reported on an almost daily basis.
'Thieves of children grab them by force even from grown-ups or kidnap them around schools, or even go into homes pretending to be visitors or census agents,' an SMS sent to an AFP journalist charged.
The impoverished west African nation, which has suffered a decade of political and military crisis, is set to hold a presidential election in October.
The wildest rumours about people disappearing for human sacrifice in rituals, particularly albinos, always circulate in the Ivory Coast in electoral years when politicians seek gains at the polls.
The kidnappings have led to calls for action from the U.N. children's agency UNICEF, which urged authorities to do everything possible to quickly identify those responsible.
'UNICEF is deeply worried by the kidnapping of children and the mutilated bodies that have been found,' Adele Khudr, UNICEF's representative in the Ivory Coast, said in a statement.