A probe has been launched after a second robbery close to Preston Bus Station in two days.
Police say the two incidents, involving mobile phones being stolen from bus passengers, may be linked.
In the latest case two boys aged 16 and 17 got off a bus and were followed into Preston, at around 5.53pm on Thursday.
Two men approached them on Cheapside and demanded their “stuff”.
One robber asked the other to “pass him a blade”.
Yesterday the Evening Post revealed how a 17-year-old boy was followed from the bus station by two thugs at 6.30pm on Wednesday.
Detectives believe the “opportunist” robbers targeted him after seeing him talking on his mobile phone.
He was approached by the robbers as he walked down nearby Percy Street.
The men tried to make conversation with him, asking him for the time but the suspicious teenager told them his phone battery “had died”.
The men then stood in front of him and demanded his phone, threatening to “knife” him.
The frightened teenager feared he had a knife as he had his hand in his pocket.
He handed over his phone and loose change and the pair fled.
Det Sgt John Crichton, of Preston CID, said: “We believe these two robberies are connected and we’re appealing for information.”
The first robber is of mixed race, 17 to 20, with a pock marked face and was stocky.
His accomplice was white, 6ft 1in, with a clear complexion and short dark hair.
He was also 17 to 20 and wore sports clothing.
Witnesses call 101.