The Israeli air force is expanding its wing of unmanned aerial vehicles built by Israel Aerospace Industries and Elbit Systems, some to be used as missile-armed gunships.

Meantime, The Jerusalem Post reports that state-run IAI, Israel's leading defense contractor, is working with Rheinmetall Defense of Germany to develop a new weapons system for aerial drones to cope with proliferating threats facing the Jewish state.

The air force plans to form a new squadron of medium-altitude, long-endurance UAVs consisting of Elbit's Hermes 900 and IAI's Heron 1 to enhance its drone capabilities.

The Israeli air force bought three Hermes 900s for evaluation in May 2010 and is waiting for final approval from the General Staff of the Israeli armed forces to purchase new platforms under a five-year procurement plan currently being finalized.

The 900 is based on the smaller Hermes 450, which has been in service for several years. It has been widely used to carry out assassination missions against Palestinian militants in the West Bank and Gaza Strip using missiles.

The 900 variant can carry double the equipment payload of the 450. These include electro-optic cameras, laser designators, radar systems, electronic intelligence and electronic warfare suites.

The Israeli military's moves to reinforce its UAV capabilities comes amid new security threats in Egypt's Sinai Peninsula following deadly clashes in early August in which Palestinian extremists killed eight Israelis.

A senior military official disclosed Friday that the air force has deployed a special UAV unit along Israel's porous 150-mile border with Sinai north of the Gaza Strip.

Israel has had to bolster its forces on that frontier, which has been dormant since the country's March 1979 peace treaty with Egypt.

Al-Qaida operatives have infiltrated into Sinai amid the unrest that followed the downfall of Egyptian President Hosni Mubarak Feb. 11. They have apparently recruited disgruntled Bedouin tribesmen. More attacks are expected.

The Israelis are also preparing for possible conflict with Iran, Syria, Hezbollah in Lebanon and Hamas in the Gaza Strip, as well as unrest linked to the Palestinians' plans to declare statehood later this month.

All these fronts will require UAVs for surveillance, reconnaissance and combat missions.

The IAI-Rheinmetall joint venture to develop a loitering weapons system for UAVs would appear to fit into this conflict scenario.

The Post reported that the system is known as WABEP, the German acronym for "weapons system for standoff engagement of individual and point targets."

The newspaper's military correspondent, Yaakov Katz, said WABEP "is a combination of Rheinmetall's KZO drone and IAI's Harop attack drone." It is understood the Harop is already in service with Turkey and India.

The propeller-driven Harop, based on the earlier Harp craft, was designed to suppress radar systems linked to surface-to-air missile systems or similar high-value targets.

It "can fly to a designated loitering position where it searches for electromagnetic signals from surface-to-air missile batteries and then dives in to destroy them," Katz reported.

Such high-risk missions have in the past largely been carried out by manned "Wild Weasel" F-4 or F-16 aircraft.

"Loitering weapons systems is considered a highly classified topic in Israel, which is believed to have developed a number of systems over the years capable of loitering over battlefields and engaging static and mobile targets," Katz wrote.

"Such systems are believed to be critical ahead of a future conflict with an enemy like Hezbollah, which has deployed tens of thousands of missiles and launchers throughout Lebanon."

Harop was unveiled by IAI at the Paris Air Show in July 2009.

Jane's Missiles and Rockets monthly reported that it has an undernose turret with optical systems that include a thermal imager and color CCD camera.

"The vehicle can attack from any direction and from any angle between the horizontal and the vertical," JMR noted. "It is armed with a high-explosive fragmentation warhead."