Prankster grabs stop sign, accidentally pulls over unmarked police car

Two pranksters were left red faced when their practical joke backfired.

The young men had grabbed stop signs from roadworks on Rundle Street in the East End of Adelaide and were directing traffic when an unmarked police car came along.

The boy was seen holding a stop sign. Source: 7 News

"He almost ran in front of him to say 'why aren't you stopping' and then he's realised that it was a cop car and that he's made a mistake," Witness Domenic Ottaviano said.

One of the men made a run for it while the other faced the music on the spot.

The runner later returned and both were cautioned.

A police officer issued a warning to the boy. Source: 7 News