A gunman on a bicycle ordered three women to wade into Boulder Creek Monday afternoon before stealing their purses, police said.The robber's gun discharged as he jumped on his bike to flee, but the man wasn't firing at the women and it may have been an accidental discharge, Boulder police spokeswoman Kim Kobel said.The women were not injured.The day after the armed robbery, many people on the path were unaware of what happened."It's scary," said Cynthia Gabino. "It's frightening because I have my son here and if they haven't found him, it makes me nervous to be out here."Police are exploring whether the robbery may be linked to a similar stick-up Thursday night when a gunman on a bike robbed a woman who was also on the Boulder Creek Path.In both cases, the gunman was a Hispanic male in his 20s, Kobel said.In the Monday afternoon robbery, the three women were relaxing by the water on the creek path near Fifth Street and Canyon Boulevard when a gunman appeared on a silver bicycle, Kobel said.He ordered the women in the creek, snatched their purses and pedaled off eastbound on the bike path, she said."I'd be surprised that someone would be so aggressive," said Linda Mohling, of Boulder.Kobel said police recovered one shell casing at the scene.