Israel sees its Iron Dome anti-rocket system as a noted success of its Gaza assault. The only problem is keeping up with demand for the interceptor missiles, their makers said on Tuesday.

“We’ve been working in non-stop shifts,” said an official with Rafael Advanced Defence Systems Ltd, which developed the system. He declined to be named for security reasons.

Equipped with five of the boxed-shaped batteries, the Israeli military says it has fired 360 missiles since the start of operation “Pillar of Defence” last Wednesday, which it says is aimed at halting rocket fire out of the coastal enclave.

Iron Dome’s radar-guided interceptor missiles target only rockets the system calculates will land in urban areas and blow them up mid-air. A military source said it was having a 90 percent success rate.

If more Hamas rockets had got through, especially the handful fired at Tel Aviv, and caused mass casualties, devastating Israeli retaliation, perhaps including a full-scale ground assault, would have been nearly certain.

Each interception costs $30,000 to $50,000, according to former Defense Minister Amir Peretz. Israel argues that proves cost-effective in preventing lethal strikes, which could trigger a vastly more expensive war.

Sometimes two missiles are used against incoming rockets. Prior to this week’s fighting Israel had stockpiled the interceptors - whose exact quantity is a state secret.

“Outstanding success rates have been achieved so far,” said Avi Leshem, an official with ELTA, a smaller firm involved in the project. He said company employees were working “night and day” to ensure the batteries stay in service.