The crackdown against those at the heart of Turkey’s abortive coup continued on Sunday night as a member of President Recep Tayyip Erdogan’s inner circle was arrested in a sign that the attempted overthrow of the government was not yet over.

Sporadic fighting at an airforce base underscored Mr Erdogan’s call to his followers to remain vigilant, with thousands of loyal Turks still crowded around public areas such as the Ataturk Airport in Istanbul and the presidential palace in Ankara.

The arrest last night of Mr Erdogan’s aide-de-camp, Colonel Ali Yazici, a man with unfettered access to the president, showed how deep the conspiracy to topple his government ran. At least four generals and more than 20 colonels have also been detained, amongst the nearly 6,000 arrested, while nearly 3,000 remain at large, according to Turkish officials. The alleged ringleader, ex-airforce chief Akin Ozturk, will be charged with treason, according to a Turkish official.