It happened at the intersection of North 3rd Street and West Allegheny Avenue in the Fairhill section of the city.
A 17-year-old was critically wounded but is now in stable condition.
SEPTA officials say 30 passengers were on the bus when the shots were fired.
At the time, police believed suspects from the shooting led them on a wild chase that ended in Kensington. The scene was captured exclusively by Chopper 6.
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Video showed the driver jumping from the moving vehicle to try and evade police. He was later taken into custody.
On Monday, police said that the chase had nothing to do with the shooting on the SEPTA bus.
Recently released surveillance images show two young men, who police believe are connected to the shooting.
"It's the highest priority to make sure that we are responding to it. For the police, the focus has been on trying to prevent critical incidents like this," said SEPTA spokesperson Andrew Busch.
SEPTA wanted to communicate to its customers that this kind of violence is unacceptable.
Officials also said crime on SEPTA buses, trains, and stations is down dramatically this year due to increased patrols and heightened surveillance coverage.
"That includes every bus, every train, every station is covered with surveillance cameras. These give us great pieces of evidence to use in these investigations," Busch said.
SEPTA says overall crime on its properties is down nearly 35% year to date.
Meanwhile, if you recognize the men in those images, please contact the police.
Anyone with information on this shooting or who recognizes the suspects is asked to contact the police.