More than 1,800 protesters were detained in Turkey following the arrest of Ekrem Imamoglu, the mayor of Istanbul, on corruption charges. Mr Imamoglu is the main potential electoral threat to Recep Tayyip Erdogan, Turkey’s president; the opposition says the charges are politically motivated and bogus. Amid the turmoil Turkey’s stockmarket fell heavily and the lira slumped against the dollar. Both clawed back some losses after emergency interventions from the stockmarket regulator and the central bank.