The injured men were taken to hospital for treatment and were in stable condition.
"This type of violent behaviour will not be tolerated and it is absolutely vital anyone with information that could assist with our investigation comes forward," the BBC quoted Detective Inspector Steven Wallace as saying.
The incident took place close to Ibrox stadium, where the two sides were playing the second leg of their Europa League second round qualifying fixture.
The match ended in a 1-1 draw, with Rangers advancing to the third round after winning the away leg 1-0 last week.