In a remote area north of Port-au-Prince, a man was reported to have offered to sell a young boy to a Canadian man for just $50.
In camps around the capital there were several reports of men being lynched after being accused by earthquake victims of trying to steal infants from tents.
The incident near Gonaives raised fears that child trafficking gangs could move into desperately poor rural areas that have yet to be properly reached by aid agencies. The gangs are also be less likely to be picked up by authorities there.
Abduction of children by child traffickers was already a chronic problem in pre-earthquake Haiti, where thousands were handed by their families into lives of domestic servitude.
"There are an estimated one million unaccompanied or orphaned children, or children who lost one parent," said Kate Conradt, a spokesman for Save the Children. "They are extremely vulnerable."
As fears for the safety of Haitian orphans grew a group of 78 children sleeping in the street outside their shattered orphanage in the capital were being guarded at night by a group of local people.