Parents have been warned to be vigilant as gardai in two counties investigate claims that children were approached by strangers.
A number of primary schools in Co Louth have sent text messages to parents to warn of two separate incidents in the county.
Gardai confirmed they were investigating both incidents but said it was too early to say whether they were sinister.
Officers in Dunleer are probing a report that a car, believed to be a black Volkswagen Golf, pulled up alongside a recently opened playground in the area and called a boy by his name as he played with friends.
Gardai said there was no adult supervising the children.
A group of children aged between eight and 10 were in the playground but they immediately ran away when the boy's name was called.
The car was then driven away and a garda spokesman said last night: "We would like to hear from anyone who was in the vicinity of the playground last Friday at around 6pm.
"As with all such reports, we are taking it seriously and making door-to-door inquiries," he added.
Gardai are also investigating an incident near Monasterboice where a man in a white van called out to a group of children on Sunday afternoon.
The children again did not respond and ran from the van.
In central Dublin, officers are checking out a report that two young boys, aged 10 and 11, were approached by a man driving a black car at Lansdowne Road.
That incident was alleged to have taken place on September 24 last but was not reported to gardai at Irishtown station until Thursday last.