Electrical problems are at least partly to blame for the closure of the Burj Khalifa's viewing platform - the only part of the half-mile high tower open yet. But a lack of information from the spire's owner left it unclear whether the rest of the largely empty building - including dozens of elevators meant to whisk visitors to the tower's more than 160 floors - was affected by the shutdown.
The indefinite closure comes as Dubai struggles to revive its international image as a cutting-edge Arab metropolis amid nagging questions about its financial health.
The Persian Gulf city-state had hoped the 828m Burj Khalifa would be a major tourist draw. Dubai has promoted itself by wowing visitors with over-the-top attractions such as the Burj, which juts like a silvery needle out of the desert and can be seen from miles around.
In recent weeks, thousands of tourists have lined up for the chance to buy tickets for viewing times often days in advance that cost more than $US27 apiece. Now many of those would-be visitors, such as Wayne Boyes, a tourist from near Manchester, England, must get back in line for refunds.
"It's just very disappointing," said Boyes, 40, who showed up at the Burj's entrance Monday with a ticket for an afternoon time slot only to be told the viewing platform was closed. "The tower was one of my main reasons for coming here," he said.
The precise cause of the $US1.5 billion Dubai skyscraper's temporary shutdown remained unclear.
In a brief statement responding to questions, building owner Emaar Properties blamed the closure on "unexpected high traffic," but then suggested that electrical problems were also at fault.
"Technical issues with the power supply are being worked on by the main and subcontractors and the public will be informed upon completion," the company said, adding that it is "committed to the highest quality standards at Burj Khalifa."
Despite repeated requests, a spokeswoman for Emaar was unable to provide further details or rule out the possibility of foul play. Greg Sang, Emaar's director of projects and the man charged with coordinating the tower's construction, could not be reached. Construction workers at the base of the tower said they were unaware of any problems.
Power was reaching some parts of the building. Strobe lights warning aircraft flashed and a handful of floors were illuminated after nightfall.
Emaar did not say when the observation deck would reopen. Ticket sales agents were accepting bookings starting on Valentine's Day this Sunday, though one reached by The Associated Press could not confirm the building would reopen then.
Tourists affected by the closure are being offered the chance to rebook or receive refunds.
The shutdown comes at a sensitive time for Dubai. The city-state is facing a slump in tourism - which accounts for nearly a fifth of the local economy - while fending off negative publicity caused by more than $US80 billion in debt it is struggling to repay.
Ervin Hladnik-Milharcic, 55, a Slovenian writer planning to visit the city for the first time this month, said he hoped the Burj would reopen soon.
"It was the one thing I really wanted to see," he said. "The tower was projected as a metaphor for Dubai. So the metaphor should work. There are no excuses."
Dubai opened the skyscraper on January 4 in a blaze of fireworks televised around the world. The building had been known as the Burj Dubai during more than half a decade of construction, but the name was suddenly changed on opening night to honor the ruler of neighboring Abu Dhabi.
Dubai and Abu Dhabi are two of seven small sheikdoms that comprise the United Arab Emirates. Abu Dhabi hosts the federation's capital and holds most of the country's vast oil reserves. It has provided Dubai with $20 billion in emergency cash to help cover its debts.
Questions were raised about the building's readiness in the months leading up to the January opening.
The opening date had originally been expected in September, but was then pushed back until sometime before the end of 2009. The eventual opening date just after New Year's was meant to coincide with the anniversary of the Dubai ruler's ascent to power.
There were signs even that target was ambitious. The final metal and glass panels cladding the building's exterior were installed only in late September. Early visitors to the observation deck had to peer through floor-to-ceiling windows caked with dust - a sign that cleaning crews had not yet had a chance to scrub them clean.
Work is still ongoing on many of the building's other floors, including those that will house the first hotel designed by Giorgio Armani that is due to open in March. The building's base remains largely a construction zone, with entrance restricted to the viewing platform lobby in an adjacent shopping mall.
The first of some 12,000 residential tenants and office workers are supposed to move in to the building this month.
The Burj Khalifa boasts more than 160 stories. The exact number is not known.
