Turkish police have detained the strongest rival to President Recep Tayyip Erdogan, a move that experts say is aimed at removing all possible contenders ahead of the next presidential election and further stretching his rule.

Authorities in Turkey have arrested dozens of people for "provocative" social media posts, after detaining the mayor of Istanbul Ekrem Imamoglu on Wednesday. Imamoglu was one of more than 100 people held on charges including corruption and aiding terrorist groups - a move that has sparked protests in Istanbul and the capital Ankara.

Ekrem Imamoglu, the mayor of Istanbul and a popular figure, had boasted jokingly that he was the only person to have beaten Recep Tayyip Erdogan’s ruling party in three local elections