Many former US intelligence officials and Iran experts believe last month's explosion at a military base near Tehran was part of a covert effort by the US, Israel and other states to disable Iran's nuclear and missile programs, The Los Angeles Times reported late Sunday.

The huge explosion ripped through the Revolutionary Guard Corps base on November 12, leveling most of the buildings and killing 17 people, including a founder of Iran's ballistic missile program, General Hassan Tehrani Moghaddam.

The newspaper said the goal of the covert effort is to derail Iran's quest for a nuclear weapons capability and to stave off an Israeli or US airstrike to eliminate or lessen the threat.

"It looks like the 21st century form of war," the paper quotes Patrick Clawson, who directs the Iran Security Initiative at the Washington Institute for Near East Policy, as saying. "It does appear that there is a campaign of assassinations and cyber war, as well as the semi-acknowledged campaign of sabotage."

Any such operation would be highly classified, and those who might know are not talking, the report said.

For years, the United States and its allies have sought to hinder Iran's weapons programs by secretly supplying faulty parts, plans or software, The Times said. No proof of sabotage has emerged, but Iran's nuclear program clearly has hit obstacles that thwarted progress in recent years.

"We definitely are doing that," the report quotes Art Keller, a former CIA case officer who worked on Iran, as saying. "It's pretty much the stated mission of the (CIA's) counter-proliferation division to do what it takes to slow Iran's weapons of mass destruction program."

Many Western experts are convinced that American and Israeli engineers secretly fed the Stuxnet computer worm into Iran's nuclear program in 2010, The Times pointed out.

The virus reportedly caused centrifuges used to enrich uranium to spin out of control and shatter, the paper said.

Neither the US nor the Israeli government has acknowledged any role in the apparent cyber-attack, the report noted.

US envoy urges allies to expand sanctions on Iran
Seoul (AFP) Dec 5, 2011 - A senior US official on Monday urged South Korea and other allies to expand sanctions on imports from Iran for its suspected nuclear weapons programme, calling the Islamic country "a pariah state".

Robert Einhorn, the US State Department's special adviser for non-proliferation and arms control, said the allies should show a "clear and unified message".

"The situation in Iran has become more and more worrisome over recent months," he said, accusing Iran of showing "little interest in seriously negotiating over their nuclear programmes".

"Iran is violating its international obligations... it is becoming a pariah state," he told reporters during a trip to Seoul.

Einhorn said allies should ban petrochemical imports from Iran, except for crude oil.

"The timeline for Iran's nuclear programme is beginning to get shorter. So it's important that we take these strong steps on an urgent basis," he said.

Britain, Canada and the US slapped sanctions last month on Iran's financial, petrochemical and energy sectors following a UN agency report that strongly suggests Tehran is researching nuclear weapons.

The European Union followed suit by expanding a sanctions blacklist against Iranian firms and individuals, although Iran dismissed the UN report as baseless.

The US Congress is also considering legislation targeting Iran's central bank -- the nexus for receiving payment for oil exports -- despite White House concerns that Iran could benefit if oil prices shoot up.

Einhorn ruled out a need for South Korea to ban imports of crude oil from Iran, saying Washington was aware of "energy security needs of countries" like South Korea.

"We would like to see a reduction in Iran's revenues from the sale of crude oil... but at the present time the oil market is very tight," he said.

South Korea in September 2010 announced a package of sanctions against Iran in line with US-backed United Nations action. But there was no ban on oil imports which provide 10 percent of South Korea's needs.

China, the European Union, India, Japan, South Korea and Turkey are the main customers for Iran's oil exports -- a major source of income of the Middle East state.