Turkish President Recep Tayyip Erdogan was in Azerbaijan Thursday to join in celebrations to mark the anniversary of the nation’s victory against Armenia following their six-week war over control of the disputed Nagorno-Karabakh territory.

Azerbaijan’s army paraded military hardware and weapons seized from Armenia through the capital Baku ahead of Erdogan’s arrival to rehearse for a large-scale victory parade on Thursday.

France24 reported the Turkish leader’s visit to Azerbaijan was an opportunity to celebrate together the “glorious victory” against Armenia for control of the mountainous Nagorno-Karabakh region, Erdogan’s office said.

Erdogan was scheduled to hold talks with Azerbaijani counterpart Ilham Aliyev and preside over the military showcasing that is the culmination of nationwide festivities for the victory, France24 reported.

The Turkish president’s visit came weeks after Armenia and Azerbaijan agreed on a deal with Russia to end clashes over Nagorno-Karabakh after a string of Azerbaijani victories in its fight to retake the disputed region.

Azerbaijan’s historic win was an important geopolitical coup for Erdogan who has cemented Turkey’s leading role as a powerbroker in the ex-Soviet Caucasus region.

Turkey backed Azerbaijan during the six weeks of fighting that erupted in late September and left more than 5,000 people dead and Ankara was accused of sending mercenaries from Syria to bolster Baku’s army, but denied the charge.

Meanwhile, Amnesty International on Thursday said in a statement that both Azerbaijani and Armenian forces committed war crimes during the recent fighting.

According to Amnesty International videos showing the decapitation of captives and the desecration of corpses had been analyzed and verified.

Amnesty International analysed 22 videos that depict extrajudicial executions, the mistreatment of prisoners of war and other captives, and desecration of the dead bodies of enemy soldiers.

Two videos show extrajudicial executions by decapitation by Azerbaijani military members, while another video shows the cutting of an Azerbaijani border guard’s throat that led to his death, the statement read.

“During the recent Nagorno-Karabakh fighting, members of the military on both sides have behaved horrendously, displaying a complete disregard for the rules of war,” said Denis Krivosheev, Amnesty International’s Research Director for Eastern Europe and Central Asia

“The depravity and lack of humanity captured in these videos shows the deliberate intention to cause ultimate harm and humiliation to victims, in clear violation of international humanitarian law.

“Both Azerbaijani and Armenian authorities must immediately conduct independent, impartial investigations and identify all those responsible. The perpetrators – as well as any commanding officers who ordered, allowed or condoned these crimes – must be brought to justice,” he said.