Turkey has summoned the US ambassador in Ankara to protest over what it called "aggressive and unprofessional actions" by US security personnel against Turkish bodyguards in Washington last week.
The move appears to be in retaliation over calls in the US for strong action against Turkish security officers who were seen hitting and kicking protesters outside the Turkish ambassador's residence in Washington during Turkish president Recep Tayyip Erdogan's visit to the US.
The Turkish foreign ministry said the US ambassador was given a "written and verbal protest" against actions said to be "contrary to diplomatic rules and practices".
The ministry said it had requested that US authorities conduct "a full investigation of this diplomatic incident".
A video shared on social media at the time appeared to show Mr Erdogan watching the melee.
Two Turkish bodyguards were briefly detained after the incident but later set free and returned to Turkey.
The United States summoned the Turkish ambassador to raise concerns over the altercation.
The incident added to the already strained ties between the US and Turkey - two Nato allies who are at odds over a US policy to back Syrian Kurdish rebels fighting the Islamic State group in Syria.
Turkey considers the fighters to be terrorists.
A Turkish foreign ministry statement said US ambassador John Bass was given a "written and verbal protest" over the treatment of two security officers that it said were "contrary to diplomatic rules and practices".
The statement said the two officers were part of foreign minister Mevlut Cavusoglu's security detail.
The Turkish ministry said it had requested that the US authorities conduct "a full investigation of this diplomatic incident".
Last week's incident is not the first time violence accompanied a visit by a Turkish leader to the US.
Last year, a similar fight erupted outside a nuclear security summit in Washington, attended by Mr Erdogan.