Israel's Defense Ministry is testing an upgraded version of Rafael Advanced Defense Systems' combat-tested Iron Dome counter-rocket system that will have "improved capabilities against an unprecedented range of threats."

The ministry didn't identify the threats but the upgrade, Iron Dome's second in recent months, follows reports that the Palestinian militants in the Gaza Strip have been test-firing a new long-range missile that could threaten cities in southern and central Israel.

The Iron Dome tests were carried out in conjunction with Rafael and state-owned Israel Aerospace Industries, flagship of Israel's defense sector. IAI subsidiary Elta Systems produces Iron Dome's advanced radar system. The command-and-control system is manufactured by mPrest Systems.

The Israelis are locked in a long-running technological battle, with the Palestinians reportedly aided by Iranian engineers and technicians who are striving to develop rockets with greater range and destructive power to pound Israeli's population centers.

The New York Times recently observed that the "missile versus missile defense campaign is being described as the most intense yet in real combat anywhere -- and as having the potential to change warfare in the same way that novel applications of air power in the Spanish Civil War shaped combat in the skies ever since."

The Americans, who have provided hefty funding for Israel's four main missile defense systems, have taken a keen interest in their capabilities.

Indeed, the pro-Israel Washington Institute for Near East Policy suggested a few days ago that to "counter the Iranian rocket and missile threat, Washington and its Persian Gulf allies should draw on lessons learned from Israel's experience in Gaza to improve the interoperability and effectiveness of their defense efforts."

That may prove to be a hard sell to the Arabs.

Meantime the Israelis, led by companies like Rafael and IAI, are producing a range of systems to form a defensive shield against everything from short-range rockets, most frequently used by Hamas and Lebanon's Hezbollah, and the intermediate-range ballistic missiles possessed by Iran and Syria.

Iron Dome, designed to intercept rockets with a range of 4-23 miles, was operationally deployed in April 2011 and its combat capabilities have steadily improved. It destroyed 84.6 percent of Palestinian rockets it engaged during an 8-day battle in November. It only seeks out rockets whose computer-tracked trajectories indicate they will hit populated areas.

Hamas and other Palestinian groups in Gaza used Iranian-built Fajr-5 missiles, smuggled into Gaza via tunnels from Egypt's Sinai Peninsula, for the first time in that clash. These targeted Jerusalem and Tel Aviv, Israel's main cities for the first time. All were shot down before reaching their targets.

But their deployment escalated a periodic conflict that is expected to involve weapons with even greater range and destructive power in the next exchange.

The November clash ended with a cease-fire but tension is mounting again after Israeli troops killed several Gazans in what the military termed "border violations."

Parliamentary elections in Israel Tuesday are also likely to heighten tensions.

Israeli Prime Minister Binyamin Netanyahu is expected to head a new government that's likely to be more hawkish than the coalition he headed after elections in 2009.

The Hebrew-language Yisrael Hayom daily reported that "Hamas is already preparing for the next clash with Israel" by test-firing two of the new rockets, type unspecified, into the Mediterranean Sea off the Gaza coast from a Hamas training base at the former Israeli settlement of Gush Katif.

The daily didn't specify a range for these missiles, beyond saying it was "dozens of kilometers."

Iron Dome is the bottom layer of a planned four-tier defense shield.

Rafael and the Raytheon Co. of the United States are developing another system dubbed David's Sling, designed to intercept rockets with a range of up to 75 miles. That's expected to enter service in 2014.

Raytheon developed the system's missile firing unit and overall logistics.

Above David's Sling, also known as Magic Wand, are Arrow-2 and the under-development Arrow-3 systems that are intended to shoot down ballistic missiles. The first Arrow battery was deployed in 2000, but the system has never been tested in combat.

Arrow-2 is currently operational. Arrow-3, which will be able to intercept missiles beyond Earth's atmosphere, is being developed by IAI and the Boeing Co. of the United States.