The victims' identities have not been disclosed beyond their initials.
Police in Istanbul have launched a large-scale investigation after a Palestinian was killed and two others were wounded in a shooting as they sat in a car, officials and media said Monday.
The killer dropped a handgun fitted with a silencer at the scene, the Istanbul Governor's Office said in a brief statement.
The Demiroren News Agency reported that the man sitting in the driver's seat was killed and his friend seriously wounded in the shooting late on Sunday. Another man, who the governor's office described as the dead man’s bodyguard, was injured in the foot.
The identities of the victims were not disclosed beyond their initials. But the apparently professional nature of the attack led to widespread speculation in the Turkish media over whether Israel may have been involved. It was also suggested that the shooting may be related to business debts.
Turkey has for years provided haven for Hamas officials. In December, the head of Israel's Shin Bet security agency said that his organization was prepared to target Hamas anywhere, including in Turkey.
The killing on Dilaver Street in the Kagithane district of north Istanbul was carried out by a masked assailant or assailants, the Demiroren News Agency said. It described the seriously wounded victim as a businessman.
Photographs showed a semi-automatic handgun with a silencer lying on the sidewalk next to a white car parked between two other vehicles. The car's rear passenger door nearest the sidewalk appeared to have been punctured by several bullets.
Video published by Demiroren showed police officers in forensics overalls scouring the area around the car and using laser pens to seemingly track the trajectory of the rounds fired. The footage also showed a body being transferred from the car to an ambulance.