Israel is drawing up plans for an attack on Iran's nuclear infrastructure that does not require America's support, it has been claimed

Defence sources told the Jerusalem Post they were considering going it alone in a strike on Iran.

Conventional military thinking states that Israel would need America's backing if only to allow Israeli warplanes to reach Iran by overflying Iraq, where the airspace is controlled by the United States Air Force.

But the paper said Israeli planners had come up with ideas that did not require support from the United States.

This comes after Ehud Olmert, the outgoing Israeli prime minister, failed to persuade President George W Bush to support an Israeli air attack in the last few months of his presidency.

It is always better to co-ordinate,'' a source, described by the Jerusalme Post as a top Defense Ministry official, said.

"But we are also preparing options that do not include co-ordination.''

Israeli officials have said it would be difficult, but not impossible, to launch a strike against Iran without clear support from America.

One option would be to use Israeli submarines firing cruise missiles from off the Iranian coast in the Gulf.

Another might be to use Israel's close links with Turkey to persuade Ankara to allow Israeli attack aircraft, air refuelling jets and pilot rescue helicopters to use Turkish airstrips.

"There are a wide range of risks one takes when embarking on such an operation,'' the Jerusalem Post said.

In September, an article in 'Defense News' said America had recently agreed to supply an improved early warning radar system to Israel precisely because this sent a signal to Iran about Washington's close military links with Israel.

"First, we want to put Iran on notice that we're bolstering our capabilities throughout the region, and especially in Israel,'' the article said.

"But just as important, we're telling the Israelis, 'Calm down, behave.

We're doing all we can to stand by your side and strengthen defences, because at this time, we don't want you rushing into the military option.'" In a related article at about the same time, TIME magazine raised the possibility that through the deployment of the radar, America wants to keep an eye on Israeli airspace, so that the US is not surprised if and when the IAF is sent to bomb Iran, a scenario Washington wants to avoid.

Last week, Iran's nuclear chief Gholam Reza Aghazadeh revealed that the country was operating more than 5,000 centrifuges at its uranium enrichment plant in Natanz and would continue to install centrifuges and enrich uranium to produce nuclear fuel for the country's future nuclear power plants.

"At this point, more than 5,000 centrifuges are operating in Natanz," said Aghazadeh, who is also the head of the Atomic Energy Organization of Iran.

This represents a significant increase from the 4,000 Iran had said were up and running in August at the plant.

The Islamic republic has said it plans to move toward large-scale uranium enrichment that will ultimately involve 54,000 centrifuges.