A girl of 11 has reported being approached by a stranger in Brighton who offered her a lift.
Sussex Police said that it wanted to repeat its advice to children not to accept a lift or go with anyone they do not know.
The girl was walking alone in Brighton, at the junction of Abbey Road and St George’s Road, at 4.30pm yesterday (Tuesday 19 July).
A man in a black car, she believed to be a Ford, asked her if she wanted a lift. She didn’t talk to him but walked on.
The man was described as being tanned, clean-shaven with brown hair and wearing a black hooded top.
Last Friday (15 July) a 10-year-old girl was approached by a man in a black Mini in Wilbury Crescent, Hove. He had offered her a lift.
Officers are also investigating an incident on Monday 4 July when a child was approached by a man in a dark car in Patcham.
Inspector Steve Warner, who is investigating these incidents to see if they are linked, said: “There is a lot of concern from parents but I do not want them or their children to be alarmed.
“We are studying CCTV and making covert and overt patrols.
“I cannot say that these incidents are linked.
“It is worrying that children were being offered lifts but we do not know what the intentions were.
“We are treating the incidents as suspicious but want to reassure children and parents not to be alarmed.
“The children concerned have reacted in the correct manner, refused to get in the car and reported the incident to the school or parent as soon as possible.
“There has been an increase in reports of suspicious activity after schools and the media have reported on the incidents, however, so far all these have proved to have an innocent explanation.
“Parents and guardians must encourage their children never to talk to or go with someone they do not know and if they feel worried about any incident they should tell a parent or teacher.”
Anyone with information regarding these incidents is asked to contact Sussex Police on 0845 6070999 or the independent charity Crimestoppers anonymously on 0800 555111.