From the roof of any of the four-storey buildings on the Egyptian side of Rafah, the town divided by the border with Gaza, dozens of structures that look like greenhouses are clearly visible in the distance. They cover the exits of some of the hundreds of tunnels dug on the Palestinian side.

The tunnels allow medicines and even electric generators and cattle to reach the Palestinian territory, whose borders have been blocked by Israel and Egypt for the past 18 months.