Biker attacked with construction sign in South Loop

CHICAGO (CBS)-- A 62-year-old man is in critical condition after he was attacked while riding a bike in South Loop.

Police said the biker was in the 2200 block of South State Street around 1 a.m. when the attacker started hitting the man with a construction sign and then with his own bike. 

The victim was taken to Northwestern Hospital in critical condition. 

No arrests have been made.