What is Israel's Iron Dome missile defence system?

It has been heavily relied upon to protect military and civilian sites from frequent barrages of rockets fired from Gaza and Lebanon in the ongoing war between Israel and Hamas.

Israel's air defences were also in operation on Saturday night, after Iran launched more than 200 drones and missiles in an unprecedented attack on Israeli territory.

Israel initially developed the Iron Dome alone after the 2006 Lebanon War, and was later joined by the United States, which has provided its defence know-how and billions in bipartisan financial support for the program.

The system has an interception rate of around 90 percent, according to Israeli defence firm Rafael, which helped design it.

Here's how it works:

- Three-part system -

The Iron Dome is one part of Israel's multi-tiered missile defence systems and is designed to intercept short-range rockets at a distance of up to 70 kilometres.

Each Iron Dome battery is made up of three main sections: a radar detection system, a computer to calculate the incoming rocket's trajectory, and a launcher that fires interceptors if the rocket is deemed likely to hit a built-up or strategic area.

It sits alongside other missile defence systems like the Arrow, to counter ballistic missiles, and David's Sling, for medium-range rocket or missile attacks.

- How much does it cost?

Each Iron Dome interceptor costs between $40,000 and $50,000 to produce, according to the Washington-based Center for Strategic and International Studies.

The think tank estimated that a complete system, including the radar, computer and three to four launchers -- each containing up to 20 interceptors -- costs around $100 million to produce.

Israel has 10 such systems in operation, according to Raytheon, which helps manufacture the Iron Dome. Other estimates have put the figure slightly higher.

- Bipartisan US support -

The Iron Dome is one of the strategic pillars of the US-Israeli alliance that has been followed by successive Democratic and Republican administrations.

In August 2019 the US Army signed a contract to purchase two Iron Dome batteries to enhance its own short-range missile defence capabilities.