The private secretary reportedly got slightly injured while Duman escaped the attack unhurt, the sources added.
In a separate incident, three gunmen also attacked a police car in Istanbul`s Okmeydani neighborhood, which is connected to Kagithane and Sisli districts on the European side, Thursday night, police said.
The assailants attacked the police car with a long barreled weapon, police added.
Police have launched an investigation into both incidents.
Earlier on Thursday, two Turkish police officers were injured in a gun-and-grenade attack in the city’s Bayrampasa district, Istanbul’s governor said.
Two female assailants said to be involved in the incident were later "neutralized" in a follow-up operation, Governor Vasip Sahin said.
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