Three different incidents targeting people on the Schuylkill River Trail in the past five days have police searching for more suspects after two have already been arrested.

A 16- and 17-year-old were taken into custody on Wednesday, ABC reported, as police are still tracking down a total of four to five young men, some on bikes, who have used a real-looking bb gun to rob trail users.

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"We have four to five males on bikes, they approach an individual that's running on the trail, walking along the trail there. … They display a handgun and demand items from that individual," Philadelphia Police Lt. John Standard told ABC.

This past fall, assaults and harassments along the river trail, mostly targeting female runners, caused alarm; the suspects in those incidents were also bicycle-riding young men, Philly.com reported.

Randy Dobin, a runner on the trail, told ABC, "It's not just been happening. It's been happening for months now."

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Police said to ABC that they recovered stolen cellphones and iPads from the juveniles arrested on Wednesday. Extra police were around the trail because of the recent incidents.