TEHRAN (Dispatches) -- An Iranian border guard has been martyred by gunmen near the border with Turkey.
The guard died in a shootout on Monday while another border guard and two engineers who were inspecting nearby water resources were wounded.
The attack happened near the town of Maku in Iran's West Azerbaijan province, about 900 kilometers, or 560 miles, northwest of the capital, Tehran.  
State news agency IRNA said the gunmen were members of Turkey's separatist PKK group and that Ankara has promised to investigate.
Turkish Foreign Minister Mevlut Cavusoglu held a phone conversation with his Iranian counterpart Muhammad Javad Zarif, Foreign Ministry spokesman Bahram Qasemi said.
Cavusoglu said PKK terrorists were behind the incident and that Turkish authorities were following up on the issue, the spokesman said.
"The Turkish Interior Minister also assured Iran’s ambassador to Ankara that the issue is being followed up, and the results will be announced,” said Qasemi.
The area near Iran's borders with Turkey and Iraq sees occasional skirmishes with terrorist groups. Last month, terrorists martyred eight Iranian border guards in clashes there.