Israel's reported to be planning to use giant, long-range Heron drones to launch stealthy pre-emptive strikes from Azerbaijan, Iran's pro-Western neighbor, on ballistic missile sites in Iran.

Iran, aware of the danger of Israeli air raids on several fronts, has been wooing oil-rich Azerbaijan to forestall possible strikes from the north, so far to no avail, however, as relations are badly strained.

The Sunday Times of London reported an undetermined number of Herons, which reputedly can carry 5 tons of payload and remain aloft for more than two days, would be used to hit Iranian missile sites with U.S.-built Hellfire missiles before the weapons could be launched.

The aim of the mooted Israeli strikes would be to knock out, or at least degrade, Tehran's ability to launch missile attacks in response to any Israeli attack on Iranian nuclear facilities.

Israeli intelligence estimates Iran has 200-300 Shehab-3 ballistic missiles operational. These have the range to hit Tel Aviv, Israel's largest population center, and strategic military targets such as air bases and Jericho ballistic missile sites.

Israeli and Azeri officials have denied recent reports that Azerbaijan, a former Soviet republic, would be used to hit Iran and there was no official verification of the Sunday Times report by Israel.

But Israel's Mossad intelligence service is known to operate in some strength in Azerbaijan to engage, with Azeri authorities, in a shadow war with Iranian intelligence operations reportedly aided by Lebanon's Hezbollah, in Azerbaijan.

Mossad also carries out spying operations inside Iran.

Israel has even denied it possesses hunter-killer unmanned aerial vehicles but it has used these repeatedly in recent years to assassinate Palestinian militant commanders, most recently during the Nov. 14-21 war in the Gaza Strip.

Israel Aerospace Industries, which builds the Heron TP II, known as the Eitan, says the UAV can fly great distances -- its range is classified -- and reach any regional target by using satellite links.

The Israelis can detect preparations for missile launches in western Iran, 1,000 miles to the east, through an AN/TPY-2 X-band radar built by the U.S. Raytheon Co. deployed in 2009 at Nevatim Air Base in the Negev Desert south of Tel Aviv.

"We'll try to kill them in the booster stage, the moment their engines are ignited," the newspaper quoted a "well-informed Israeli military source" as saying.

"If that happens, and it isn't as easy as it sounds, then the remaining missiles will be finished by our Air Defense Command."

There has been much speculation Israel might also seek to launch manned airstrikes against Iran from Azeri airfields to avoid the risks of a 2,000-mile round trip, with at least two in-flight fuellings.

Alternatively they could arrange for the strike jets flown from Israel to land in Azerbaijan after hitting Iranian targets rather than fly the aircraft -- some could have battle damage -- all the way back to Israel.

Azerbaijan has four Soviet-era military airfields that could accommodate Israeli strike jets and aerial tankers and these bases are only a few hundred miles from most of the targets Israel wants to hit in Iran.

Deploying several dozen F-16I and F-15I aircraft in Azerbaijan would be difficult to achieve without detection.

Sending in a squadron or more of Heron Eitans might be less obvious, despite the craft's 75-foot wingspan.

All of this, of course, is speculative. Neither Israel nor Azerbaijan is going to openly discuss such a highly classified and politically perilous military operation.

Israeli Prime Minister Binyamin Netanyahu has repeatedly threatened to launch pre-emptive strikes against Iran to prevent it acquiring nuclear weapons that would challenge Israel's monopoly in the Middle East.

The United States argues against Israeli strikes, claiming they'd ignite a regional war.

Netanyahu has stayed his hand but had made clear he views Iranian nuclear weapons as an existential threat to the Jewish state.

Meantime, Israel has become a major arms supplier to Azerbaijan. In 2011, Israel signed a $1.6 billion arms deal with the government in Baku, Azerbaijan's capital on the Caspian.

That includes up to 60 UAVs, supposedly for surveillance and reconnaissance.

In return, the autocratic Baku regime of President Ilham Aliyev, considered a key U.S. ally in the region, provides Israel with oil from the Caspian.