He was diagnosed with concussion and arm injuries.
Pancic, who was recovering following the assault, told RFE/RL that he suspects the two men were following him before the beating aboard a packed bus.
He is widely known for his uncompromising stance against runaway nationalism and sports hooliganism.
"I didn't understand what they were saying [during the attack], but it's obvious that this was a targeted attack," Pancic said. "This was no mistake, no robbery, but a personally targeted attack."
The police said they were looking for the assailants, who fled the scene after leaving the metal bar at a bus stop.
Pancic, 45, has been a regular fixture on the Serbian scene as a political columnist since 1999. Aside from his work for RFE/RL and "Vreme," Pancic has written for a number of newspaper and other publications in the Balkans and elsewhere.