A teenage boy and girl were hit over the head by robbers who targeted them in a Rotherham park.
The victims, both aged 16, were approached in Clifton Park by four men who demanded money.
They were both struck over the head when they refused to hand over their valuables, with the boy suffering a swollen eye and a cut, while the girl was left with a bump.
The robbers stole a Nikon Cool Pics camera and a pencil case from the boy's rucksack.
E-fits of two of the suspects have now been released by South Yorkshire Police.
A force spokeswoman said: "A boy and a girl, both 16, were inside the park at around 6pm on Saturday, May 21 when they were approached by four men, who were described as being Eastern European in appearance.
"One of the men demanded money and, when the victims refused, it is alleged he hit the boy to the head.
"They then took his black Nikon Cool Pics camera from his rucksack as well as a pencil case, which was later found close by.
"One of the men approached the girl and tried to take her mobile phone. She was hit to the head.
"The suspects fled in the direction of Clifton Park Museum.
"The girl suffered a bump to the head, while the boy had a swollen eye and a cut to the head."
The robbers police want to trace were between 16 and 19-years-old, around 5ft 4ins tall and wore dark tracksuits and peak caps.