Turkish police detained 12 suspects including the head of a rival criminal clan over the murder of Jovan Vukotic, a Serbian mob boss. The Turkish National Police announced on Wednesday the capture of Radoje Zivkovic, head of the Kavac clan, Zdravko Perunovic and 10 other suspects linked to the murder in Istanbul’s Şişli district on Sept. 8.

Vukotic, who runs the “Skaljari” clan based in Montenegro, was captured in Türkiye three years ago and extradited to Serbia. After he was released from detention, he illegally entered Türkiye, Turkish authorities said in a statement. He was in a car with his wife and child when two gunmen on a motorcycle approached it and fired fatal shots. His family and the driver survived the attack. The family was traveling to a shopping center when the attack occurred.

An investigation by Turkish police organized crime and intelligence units revealed the murder was perpetrated by Zivkovic's “connections” in Türkiye and the suspect and others were detained on Sept. 16. Police also confiscated 11 fake IDs, six fake passports and two guns used in the murder.

Turkish media outlets reported that Vukotic was wanted with an international search warrant. Ihlas News Agency (IHA) reported that the murder stemmed from a feud between the Kavac and Skaljari clans. The feud reportedly dates back to 2015, over the “disappearance” of 300 kilograms (661 pounds) of cocaine from an apartment in Spain’s Valencia. Media outlets reported that the conflict between criminal clans led to the murders of 40 people in various countries, from Montenegro to Serbia, Austria and Greece, since 2015.