Police are hunting a man who tried to rob two groups of teenage girls at knifepoint in a Liverpool park.
Two 13-year-olds were threatened by a man in Stanley Park, Anfield, on Friday night. He ordered them to hand over their mobile phones but they ran off.
A second group of girls, all 14, were also threatened with a knife, at 1800 BST on Saturday. He stole three mobile phones from the.
Police have appealed to anyone with information to contact them.
The robber is described as white, aged 17 to 22, 6ft (1.8m) and of slim to medium build.
He was wearing a dark jacket and balaclava.
Det Con Andy Bason, of Merseyside Police, said: "The actions of this man have left the victims extremely traumatised and it is imperative that he is identified and brought to justice."
He said these incidents were rare but patrols had been stepped up in the area as a precaution.