TEHRAN, Iran (AP) — An Iranian semi-official news agency says the country’s foreign ministry has summoned Azerbaijan’s ambassador to Tehran over the killing of an Iranian guard by Azeri forces in a border incident.

The Fars news agency says the unarmed 18-year-old Iranian guard had strayed into Azerbaijan, and was detained and shot dead by Azeri border guards on Wednesday.

Iran and Azerbaijan share about 470 miles — 760 kilometers — of a common land and sea boundary.

Border incidents happen occasionally. In July, an Azeri border guard was shot dead after illegally crossing into Iran.

Far’s report late Thursday said the Azerbaijan ambassador was told the killing of the Iranian guard was a violation of international norms and neighborly relations.