Israel has deployed a third Iron Dome missile defence system near its northern borders with Syria and Lebanon, security sources said on Tuesday.
The Iron Dome systems have been deployed alongside a U.S.-supplied Patriot battery, which has been stationed in the north for years, as Israel is on the alert for weapons leaking out of the Syrian civil war that could be turned on the Jewish state.
Two Iron Dome batteries, which use radar-guided interceptor missiles to shoot down short-ranged rockets, had already been deployed there.
Israel has said it could use military action to prevent chemical weapons and advanced arms from Syria slipping into the hands of militant groups as a result of the civil war there.
It declined to comment on whether it was responsible for bombing a Syrian arms complex last week.
Israel has maintained official silence over the raid, but its defence minister said the incident showed that Israel was serious about preventing the flow of heavy weapons into Lebanon.
Syria's ally Iran said Israel would regret the air strike, but did not say whether either country planned a military response.
A military spokesman declined to give details on the Iron Dome deployment, but described it as routine.
Reporting by Dan Williams; Writing by Ari Rabinovitch; Editing by Robin Pomeroy