Iranian President Mahmoud Ahmadinejad has triggered a diplomatic furore over his request to lay a wreath at the World Trade Centre site to commemorate the September 11 attacks.

Even before setting foot on US soil for the upcoming UN general assembly, the Iranian leader has managed to ruffle American feathers by asking to visit what is considered a sacred site.

Mr Ahmadinejad, who is to due to arrive on Sunday to address the assembly, had asked New York city and the US secret service earlier this month for permission to visit ground zero.

A statement by New York police commissioner, Raymond Kelly, that said the city was considering the application prompted outrage from politicians, quickly resulting in a refusal.

Rudy Giuliani, who was mayor during the 9/11 attacks and is now a Republican presidential candidate, branded Mr Ahmadinejad’s request “outrageous” and described him as “a man who has made threats against America and Israel; is harbouring [Osama] bin Laden’s son and other al-Qaida leaders; is shipping arms to Iraqi insurgents; and is pursuing the development of nuclear weapons.”

Hillary Clinton, the Democratic presidential candidate, said it was “unacceptable” for Mr Ahmadinejad “to visit the site of the deadliest terrorist attack on American soil in our nation’s history”.

Mohammad Mir Ali Mohammadi, spokesman for the Iranian mission to the UN, described the refusal as unfortunate.

“President Ahmadinejad intended to lay a wreath at the site of ground zero in order to pay tribute to the victims of the terrorists attack of September 11 2001. We are hopeful that we can still work something out with the police department.”

Mr Ahmadinejad is scheduled to speak at Columbia University on Monday at a forum of world leaders organised by the college’s school of international and public affairs. It promises to be a raucous affair.

The Iranian leader has been dogged by protesters during past visits. A year ago, after he was invited to address the same Columbia forum, the invitation was withdrawn because his appearance might not “reflect the academic values of the event”.

The president’s visit to the US comes amid intense speculation of a possible American strike at Iran’s nuclear facilities over Tehran’s refusal to halt its uranium enrichment programme.

The US is trying to drum up support for a third round of UN sanctions against Iran, with France on board, but with Russia and China reluctant to further pressure Iran.

Apart from the nuclear issue, Washington has stepped up accusations against Iran over its alleged support for Shia militants in Iraq who are targeting American soldiers with explosive devices.

In a television appearance earlier this week, Mr Ahmadinejad said his country wanted peace and friendship with the US, despite mounting tensions.

The US has also denied a visa to Iran’s UN ambassador in Geneva to attend next week’s general assembly meeting because he was allegedly involved in the 1979 US hostage crisis in Tehran, a UN official said.

Shares in Northern Rock went into freefall again today, crashing almost 30% to a new all-time low after the Treasury warned that it will not protect new customers who open savings accounts with the troubled bank.

As the crisis around the bank deepened, «business.guardian.co.uk» plunged 71p to 185p in the first hour of trading this morning.

The sharp fall came as traders digested an announcement from the Treasury that «business.guardian.co.uk» in an effort to stop the run on Britain’s fifth-largest mortgage lender, does not apply to new account holders.

The government will only protect accounts that existed at midnight last night, and those of customers returning to Northern Rock after rushing to close their accounts in recent days.

“This guarantee covers future interest payments, movements of funds between existing accounts, and new deposits into existing accounts. The guarantee will also cover accounts re-opened in the future by those who closed them between Thursday 13 September and Wednesday 19 September, inclusive,” said the Treasury.

It added that it would be “unfair on other banks and building societies” if the protection were extended to any new customers in the future.

But without such protection, potential customers may be unwilling to trust Northern Rock with their savings, in the aftermath of the run in the bank this week, putting further pressure on its liquidity.

Yesterday «business.guardian.co.uk» amid fears that the bank would be sold at a knock-down price. Northern Rock shares were trading at more than 12 each earlier in the year, valuing the company at over 5bn. The current price values the bank at less than 800m.

The following conventions, conferences and meetings are scheduled for this week in San Francisco:

– BEA Systems Inc. World 2007, Monday through Wednesday, Moscone Center.

– American SAP Users’ Group Western Regional Meeting, Monday through Wednesday, Marriott.

– Big Brothers & Big Sisters of America Western Regional Conference, Monday through Wednesday, Holiday Inn Golden Gateway.

– State of California Auto Dismantlers Association Annual Convention, Thursday through Saturday, Stanford Court.

– Civil Service Employee Agents Association Annual Agents Convention, Thursday through next Sunday, Westin St. Francis.

– American Roentgen Ray Society Regional Symposium, Friday and Saturday, InterContinental Mark Hopkins.

– Council on Foundation Annual Conference, Friday through Sept. 19, Hilton Hotel.

– National College of District Attorneys White Collar Crime Symposium, Saturday through Sept. 20, Holiday Inn Fisherman’s Wharf.

– Texas Club of Internists Fall Clinical Meeting, Saturday through Sept. 19, InterContinental Mark Hopkins.

– American Hospital Association Center for Healthcare Governance, Saturday through Sept. 19, InterContinental Mark Hopkins.

Source: San Francisco Convention & Visitors Bureau