Dozens of people including journalists have appeared before a court in Istanbul, accused of attending banned demonstrations and disobeying police orders to disperse during anti-government protests.

Turkey started hastily organized mass trials on Friday to prosecute some of the hundreds of people who took part in the widespread demonstrations over the jailing of Istanbul’s mayor Ekrem Imamoglu, the major rival to President Recep Tayyip Erdogan.

The detention of Istanbul's popular mayor risks undermining Turkey's move to end the PKK militant group's 40-year-old insurgency - a plan relying heavily on the government's nascent, delicate cooperation with the pro-Kurdish DEM Party.