Turkey has warned it may reconsider its friendship with the United States unless it extradites the Islamic cleric accused of masterminding Friday's attempted coup. The country's prime minister, Binali Yildirim, has rejected Washington's demand for evidence that Fethullah Gulen was involved in the failed putsch. Mr Gulen, who lives in Pennsylvania, denies any involvement in the unrest - and Ankara is set to submit a formal request for his extradition in the coming days. The tension comes as Recep Tayyip Erdogan's post-coup purge continues, with close to 20,000 members of the army, judiciary, police and civil service detained or suspended. More than 6,000 soldiers are in custody - and footage has shown some of them stripped to their underwear and handcuffed on the floors of sports halls. One of those arrested was former air force chief Akin Ozturk, who was paraded in front of cameras and accused of being a co-leader of the coup. The general has denied the allegations - insisting he was one of those trying to quash the unrest, which he believes was orchestrated by Mr Gulen.

President Erdogan has said Turkey's parliament must consider reintroducing the death penalty for those involved in the plotting, saying: "In democracies, whatever the people say has to happen." However, any move towards capital punishment could further hamper Turkey's long-held ambition of joining the European Union. The trading bloc's foreign ministers issued a joint statement which said "the unequivocal rejection of the death penalty is an essential element" of membership. Mr Yildarim said 232 people had been killed - less than the 290 suggested earlier by the foreign ministry - and more than 1,500 wounded since coup plotters ordered tanks into major cities and sent fighter jets to fire on key government installations on Friday. President Erdogan has reportedly given his country's air force orders to shoot down any military helicopters taking off from Istanbul. Leave has been cancelled for all civil servants until further notice and the prime minister's office asked any on holiday to return to their duties. The purge of state structures and presence of F-16 jets suggests authorities fear the threat against Mr Erdogan is not over, even following thousands of arrests.