Turkish security forces chasing robbers have killed four suspected militants of the Kurdistan Workers’ Party (PKK) in the country’s southeastern province of Diyarbakir, a local governor says.

Robbers attacked an armored vehicle carrying money belonging to a state-run bank in the town of Bismil in Diyarbakir late on Tuesday, and stole 110,000 Turkish lira (37,000 US dollars), the provincial governor’s office said in a statement.

Following the raid, the security forces that were dispatched to catch the robbers clashed with suspected PKK militants and killed four of them, the statement said, without clarifying how and if the robbers and the PKK militants killed were connected.

There has been a deadly conflict between the PKK and Turkish security forces since July, when Turkey began airstrikes against purported Daesh targets in Syria as well as PKK positions in Turkey and Iraq after a Daesh bomb attack left 32 people dead in the southeastern Turkish town of Suruc.

On Monday, Turkish Interior Minister Selami Altinok said over 2,000 PKK militants have been killed in Turkish military operations since July 22.

Over 150 Turkish soldiers and police forces have also been killed in the fighting, according to Turkish pro-government media.

The PKK has been fighting for an autonomous Kurdish region inside Turkey since 1984. The clashes have reportedly left some 40,000 people dead.​

A shaky ceasefire between Ankara and the PKK that had stood since 2013 was declared null and void following the Turkish military campaign against the militant group.