WASHINGTON — Western and U.N. nuclear officials are evaluating a secret Iranian technical document that appears to show the country’s nuclear scientists testing a key component used in the detonation of a nuclear warhead, according to intelligence officials and weapons experts familiar with the document.

The document, if authentic, could be one of the strongest pieces of evidence pointing to a clandestine Iranian effort to build nuclear weapons, said former intelligence officials and weapons experts.

They were responding to a London newspaper report of alleged sophisticated research by Iran on one of the final stages in the construction of a nuclear device.

Excerpts from the technical paper detail a four-year program by Iranian scientists to develop and test a neutron initiator, a device used to trigger a nuclear explosion.

Former U.S. intelligence officials said the document must be evaluated and accurately dated before any conclusions can be drawn.

But one former Iran specialist said the paper would be tantamount to a “smoking gun.”

Connecticut: 50-car pileup

Police say at least 50 cars crashed in a chain-reaction collision on a wet Shelton highway that was turning icy, and 46 people reported minor injuries. None of the injuries were life-threatening; six people were taken to hospitals. Highway 110 was closed for more than five hours.

Iraq: U.S. tip about blast came too late, officials say

The U.S. military had warned of an imminent attack hours before Tuesday’s deadly bombings in Baghdad, but the tip came too late to act on, Iraqi security officials said Sunday. On the morning of the attacks, Iraqi Lt. Gen. Abboud Qanbar said, Baghdad’s security command received intelligence from the U.S. military that insurgents would soon carry out three attacks, including one in or near the protected Green Zone. He said the tip indicated there would be two car bomb attacks in the morning and another later in the day. Three major explosions shook Baghdad about five hours later. At least 127 Iraqis died and more than 500 were wounded.

Britain: Prince William not ‘shadow king,’ palace says

Buckingham Palace denied a newspaper report that the queen is passing more of her duties to her grandson, Prince William, to groom him to be “shadow king,” bypassing his father, Prince Charles, who is next in line to the British throne. The Mail on Sunday said on its front page that Queen Elizabeth II is handing over a substantial part of her public duties to the prince to ease the 83-year-old monarch’s work load. The report said it obtained a classified Treasury note showing the prince will incur more expenses because he will be undertaking duties on behalf of the queen.

Afghanistan: Eight police officers killed in attack

Eight Afghan police officers were killed today in an attack on a checkpoint in northeast Afghanistan. Mohammad Akbar Barakzai, the governor of Baghlan province, said the officers, who were members of the Afghan National Police, died after enemy militants attacked them before dawn. The police unit was providing security for the highway.

Israel: Millions of dollars funneled into settlements

The Israeli Cabinet voted Sunday to pour millions of dollars of new funding into Jewish settlements in the West Bank, including several hardline communities that have put up fierce resistance to government-imposed construction restrictions. Prime Minister Benjamin Netanyahu’s plan drew accusations that he is trying to buy off settlers who are furious over the construction limits. Netanyahu last month announced a 10-month moratorium on the building of new homes in the West Bank.

From Herald news services