Mustafa Çalışkan, a police chief of Istanbul, was on the frontline of efforts to thwart putschists during the July 15, 2016 coup attempt by military infiltrators of the Gülenist Terror Group (FETÖ).

In his newly released book about that day, Çalışkan reveals how the police discovered a van full of explosives at a military school in Istanbul. "We found a van in the courtyard of Air Warfare School. Inside, there was 24 pieces of C4 explosives, enough to blow up a conference or sports hall. There were also 222 hand grenades and a large number of munitions inside.

I don't know where they planned to blow up but it was likely that [putschists] would detonate it at a mosque or church so they could incite chaos and show people that nowhere was safe, in the case of a failure of the putsch," he wrote. Çalışkan, who heard the coup attempt around the time when putschists started to take over several sites, including a bridge connecting the city's two sides, joined fellow police officers and civilians on the bridge in their efforts to stop the putschists. His two bodyguards were shot by putschists and Çalışkan himself was guarded by a large crowd of civilians who confronted the putschists.

Throughout the coup attempt, he coordinated police operations to stop putschists who outgunned police officers. With the aid of a strong public resistance, the Istanbul police managed to fend off putschists. Çalışkan is also credited for the liberation of Istanbul's Atatürk Airport from putschists, shortly before a plane carrying President Recep Tayyip Erdoğan landed there.

Erdoğan was naturally the main target of the putschists. Coup plotters sent two teams of assassins to take him out while he was on vacation in southwestern Turkey. Erdoğan learned about the attempt beforehand and left his hotel. He then secretly flew to Istanbul and called upon the public "to take to the streets" against the putschists. In his book "July 15, Night of Apocalypse, Resistance and National Strike," Çalışkan says putschists sent a column of 10 tanks to Kısıklı, the Istanbul district where Erdoğan's residence is located, but police managed to stop them by parking trucks, concrete mixers and other heavy vehicles in their way.