CHICAGO (CBS) — Two teenage boys were arrested early Thursday and charged as juveniles, after allegedly assaulting one man and robbing another on a Red Line train in the Loop.

About midnight near the State and Lake stop, the victim found two police officers and told them someone had just threatened to shoot him on a CTA subway train, according to Central District police Lt. Robert Lajewski.

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After the officers accompanied the victim down to the platform to investigate, a train approached and police stopped the two suspects when they got off the train and the victim identified them.

Police found a second victim when a man getting off the train saw police with the teens and said: “Hey, they just robbed me,’’ the lieutenant said.

That man said the suspects took his mp3 player and cell phone, which were recovered.

The 16-year-old boys were arrested, and one was charged with robbery and the other with assault, Lajewski said.

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The boys are not being identified because they are juveniles, but the lieutenant said they are from the South Side.

This was at least the second robbery that resulted in an arrest on the Red Line in the past 72 hours.

At 1:40 a.m. Tuesday, Nepal native Raman Dhital was riding a Red Line train from downtown, when three stole his video camera and hit him. A team of Guardian Angels caught the suspects and held them for police.

The suspects — Ryan Mitchell, 19, of the 9600 block of South Langley Avenue; and Hoyle Marshall, 22, of the 9600 block of 9600 block of South Union Avenue — are charged with robbery and battery causing bodily harm.

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The Sun-Times Media Wire contributed to this report.