Several independent Serbian media reported attacks on it social media platforms overnight, the Beta news agency reported.
It said that the agency Instagram account had been targeted in a suspected bot attack and added that the attack appeared designed to temporarily disrupt its ability to publish through the platform ahead of Serbia's October 25 parliamentary elections.
Similar online attacks were reported by the weekly Vreme, democracy watchdog CRTA, and news portals Kompas and Masina.
The Serbian regime has been alleged to have used similar online attacks against independent media in the past.