When Israel launches air strikes and artillery bombardments on Gaza, Palestinians have few sources of protection. But when Palestinians fire rockets into the Jewish state, its citizens can bank on one the world’s most tried and tested air-defence systems for security — the Iron Dome.

Hamas, the Palestinian militant group that controls the Gaza Strip, has since Monday launched about 1,800 rockets on Israel, targeting major cities such as Jerusalem and Tel Aviv as well as other towns.

The Islamist movement has maintained its barrage even as Israeli fighter jets, artillery and tanks have pounded the impoverished Palestinian territory of 2m people. At least 122 people have been killed since Monday in Gaza, including 31 children and 20 women, and 900 others wounded, Palestinian medical officials said.