An argument on an early-morning SEPTA bus left one man with lacerations after his attacker pulled out a blade, police said.

The stabbing happened at approximately 3 a.m. Thursday at 46th and Market aboard a westbound Market-Frankford Night Owl bus — which travels the route of the El overnight, a SEPTA spokeswoman said. 

The victim was treated by paramedics and released. 

Philadelphia police said they were investigating.