'I’m calling from Israeli intelligence. We have the order to bomb. You have two hours'

The call to Mahmoud Shaheen came at dawn.

It was Thursday 19 October at about 06:30, and Israel had been bombing Gaza for 12 days straight.

He'd been in his third-floor, three-bedroom flat in al-Zahra, a middle-class area in the north of the Gaza Strip. Until now, it had been largely untouched by air strikes.

He'd heard a rising clamour outside. People were screaming. "You need to escape," somebody in the street shouted, "because they will bomb the towers".

As he left his building and crossed the road, looking for a safe place, his phone lit up.

It was a call from a private number.

"I'm speaking with you from Israeli intelligence," a man said down the line, according to Mahmoud.

That call would last more than an hour - and it would be the most terrifying call of his life.