Senior Israeli officials accused Sudan on Thursday of playing a key role in an Iranian-backed network of arms shipments to hostile Arab militant groups across the Middle East, a day after a mysterious explosion rocked a weapons factory near the North African country's capital.

The tough words were likely to add to Sudanese suspicions that an Israeli airstrike was behind the blast. Israel has both the motive and means to carry out such an airstrike, and Sudan has accused Israel in the past of operating on its territory.

Israel considers Iran to be a grave threat, citing Iranian calls for Israel's destruction, suspicions that Iran is developing a nuclear bomb, and Iran's support for militant groups on Israel's southern and northern borders. Israeli officials have long contended that Sudan is a central player in Iranian efforts to funnel weapons to Hamas militants in the Gaza Strip and Hezbollah guerrillas in Lebanon.

Sudan claimed Wednesday that Israeli airstrikes caused an explosion and fire at a military factory south of the capital, Khartoum, killing two people. It said four aircraft hit the Yarmouk complex, setting off a huge blast that rocked the capital before dawn.

"They used sophisticated technology," Sudan's information minister, Ahmed Belal Osman, said without elaborating. There was no word on the identities of the two people who were killed.

Israeli Prime Minister Benjamin Netanyahu refused to comment on the incident at a news conference with the visiting Italian premier, Mario Monti.

But Netanyahu's vice premier, Moshe Yaalon, said Israel had "nothing to cry about."

Speaking to Israel Radio, Yaalon described Sudan as an important base for both Iranian and al-Qaida militants to carry out mayhem.

"It's used as a base to disseminate terror, in Africa and in our direction too," he said. "There's no doubt that there is an axis of weapons from Iran via Sudan that reaches us, and not just us. It shows Iran continues to be a rogue state stirring up not a few conflicts in the region."

Sudan has been engaged in various armed conflicts for many years. Its government has been at war with rebels in the western region of Darfur and with its neighbors in South Sudan, which broke away to become Africa's newest country in 2011.

Sudan's president, Omar al-Bashir, has been indicted by the International Criminal Court on charges of genocide, war crimes and crimes against humanity.

Sudan was a major hub for al-Qaida militants and remains a transit for weapon smugglers and African migrant traffickers.

The U.S. imposed economic, trade and financial sanctions against Sudan in 1997, citing the Sudanese government's support for terrorism, including its sheltering of al-Qaida founder Osama bin Laden in the mid-1990s. In 1998, American cruise missiles bombed a Khartoum pharmaceutical factory suspected of links to al-Qaida.

Jonah Leff, who monitors Sudan for the Geneva-based Small Arms Survey, said it remained unclear what caused Wednesday's blast. Although the U.S. also maintains warplanes in the region, he said Israel was the likely culprit if it turned out to be an airstrike.

"I can't think of anyone other than Israel that would have conducted it," he said, noting the Iranian ties with Sudan, the past reports of Israeli airstrikes in Sudan and Israel's emerging alliance with South Sudan.

Israel has grown increasingly concerned about the arms flow to both Hezbollah and Hamas. Israel believes that both groups possess tens of thousands of rockets, anti-tank and anti-aircraft missiles and other advanced weapons.

These concerns have been illustrated by a pair of incidents in recent weeks. Earlier this month, Israel shot down an unmanned Iranian-made aircraft launched by Hezbollah. This week, Hamas fired dozens of rockets into southern Israel during a brief flare-up of violence.

Israeli officials believe many of these weapons follow a circuitous route that begins in the Iranian port of Bandar Abbas, stretch through Dubai and on to Sudan, before crossing Egypt's lawless Sinai desert and into Gaza through underground tunnels. The Israeli air force periodically targets these tunnels in an attempt to halt the flow of weapons.

A number of other operations over the years have also been attributed to Israel. In 2009, Sudan accused Israel of carrying out an airstrike on an arms convoy near the Red Sea in eastern Sudan.

The following year, Hamas accused Israel of assassinating a top militant in a Dubai hotel room. Israel never confirmed involvement, but claimed the militant, Mahmoud al-Mabhouh, had worked in Sudan and played a critical role in shipping advanced Iranian rockets to Gaza.

Israel possesses a sophisticated air force of U.S.-made F-15 and F-16 warplanes, and has a record of carrying out daring air raids over enemy skies. In 1981, Israel destroyed an unfinished nuclear reactor being built in Saddam Hussein's Iraq. In 2007, it destroyed what the U.S. has said was a nearly finished nuclear reactor in neighboring Syria.

In recent months, Israel has hinted that it is ready to use its air force against Iran as well. Israel believes Iran is pursuing nuclear weapons — a scenario that it considers a threat to its very existence. Iran says its nuclear program is for peaceful purposes only, but Israel and many Western countries dismiss this.

Israel has threatened to strike Iranian nuclear facilities if it concludes that international sanctions fail to stop the Iranians.

Some Israeli commentators said that if Israel had indeed carried out an airstrike that caused Wednesday's blast in Sudan, it might have been a dress rehearsal of sorts for an operation in Iran. Both countries are roughly 1,000 miles (1,600 kilometers) away from Israel, and an air operation would require careful planning and in-flight refueling.

But there are key differences as well. Iran has a far more advanced air-defense system than Sudan, and its nuclear facilities are scattered across the country in heavily fortified sites.

"The Iranians ought to be worried by Israel's ability to deceive and achieve surprise at such a vast distance from home — if it was Israel that carried out the attack," wrote Alex Fishman, a military affairs commentator with the Yediot Ahronot daily. But, he noted, "a flight over Iran or to Iran is a more complicated effort."

Isaac Ben-Israel, a retired Israeli air force general and a former head of the Israeli space agency, said he had no idea what caused the explosion but that anyone with an advanced air force could pull it off.

He noted that Arab countries tend to blame Israel for any attack that takes place on their soil. In the case of the explosion in Sudan, he said Israel had no interest in confirming or denying its involvement.

"Even if it wasn't us," he said, "there's no damage in letting them think it was."


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