Recep Tayyip Erdogan

The arrests come just a day after three police officers were killed during a siege in the town of Yalova.

Istanbul's chief prosecutor accuses Ekrem Imamoglu and 400 others of running a corruption network.

Erdogan's critics claim that he has become a latter-day Sultan in Turkey, dismantling human rights, cracking down on dissent and weaponising the courts

The ceremony took place under tight security at a cave in Iraqi Kurdistan - the disarmament process is expected to last all summer.

The arrest operation is the fifth after Turkey jailed Istanbul's mayor and leading opposition candidate Ekrem Imamoglu.

Erdogan has led Turkey for 22 years, and been president for the past 11, but cannot run again without changing the rules.

Istanbul Mayor Ekrem Imamoglu has relied on social media to stay in touch with supporters from jail.

Students and journalists are among the 189 people on trial in Istanbul after protests last month.