"A few hours ago, the EU Ambassador in Sudan was assaulted in his own residency. This constitutes a gross violation of the Vienna Convention," Josep Borrell said on Twitter, Anadolu Agency reported.
Borrell pointed out that the security of diplomatic premises and staff is "a primary responsibility" of Sudan's authorities as well as an obligation under international law.
Fighting erupted on Saturday between the Sudanese army and paramilitary Rapid Support Forces in the capital Khartoum and its surroundings.
Since then more than 180 people have been killed and 1,800 injured in armed clashes between the military rivals, UN envoy Volker Perthes said on Monday.