Washington has worked discreetly to block the supply of Iranian and Syrian weapons to Islamist groups in the Middle East, Britain's Guardian newspaper said on Tuesday, citing US diplomatic cables obtained by WikiLeaks.

The United States, in many cases using secret intelligence provided by Israel, had pressured Arab governments not to cooperate with arms smuggling to Palestinian group Hamas or Lebanon's Hezbollah, it said.

The details were part of 250,000 diplomatic cables obtained by the website WikiLeaks that are being made public.

US State Department cables showed Washington warned Sudan in January 2009 not to allow the delivery of unspecified Iranian arms that were expected to be passed to Hamas in the Gaza Strip around the time of an Israeli offensive there in which 1,400 Palestinians were killed, the Guardian said.

US diplomats were told to express 'exceptional concern' to Sudanese authorities, it said.

Saudi Arabia, the United Arab Emirates, Oman and Chad were informed of the alleged Iranian plans and warned that any weapons deliveries would be in breach of UN resolutions banning Iranian arms exports, the newspaper said.

In March 2009, CBS News reported that Israeli aircraft had attacked a suspected arms smuggling convoy in Sudan two months earlier, killing more than 30 people, to block an arms delivery to Hamas in Gaza.

State Department documents record that Khartoum then privately accused Washington of carrying out two air attacks in eastern Sudan: one in January 2009, with 43 dead and 17 vehicles destroyed, and another on February 20, with 45 dead and 14 vehicles destroyed.

In March 2009, the United States informed Jordan and Egypt about new Iranian plans to ship a cargo of 'lethal military equipment' to Syria with onward transfer to Sudan and then to Hamas, the Guardian said.

Washington asked that the planes be forced to land for inspection or denied overflight rights, it said. It is not known whether any deliveries went ahead.

In April 2009, Egypt's interior minister, Major-General Habib el-Adli, was described in US cables as being behind the dismantling of a Hezbollah cell in Sinai as well as 'steps to disrupt the flow of Iranian-supplied arms from Sudan through Egypt to Gaza', the paper said.

At the end of that month, Egypt's intelligence chief, Omar Soleiman, told US officials Egypt was 'succeeding' in preventing Iran from channelling financial support to Hamas.

'Egypt had sent a clear message to Iran that if they interfere in Egypt, Egypt will interfere in Iran, adding that EGIS (Egyptian intelligence service) had already begun recruiting agents in Iraq and Syria,' Soleiman said, according to the Guardian.-Reuters