Apple Inc.?s stores attracted long lines of shoppers for the debut of the latest iPhones, indicating healthy demand for the bigger-screen smartphones.

The iPhone 6 and the 6 Plus went on sale Friday in Australia, Hong Kong, Singapore, Japan, France, Germany, the U.K. and the U.S. Shoppers in New York and San Francisco had already formed lines in the past two days to be among the first to buy the gadgets.

Apple fans also lined up at stores at Ala Moana and on Kalakaua Avenue in Waikiki.

At Apple’s store on Fifth Avenue in New York, police officers put up barricades as the line stretched more than 10 blocks and the crowd cheered continuously for the 15 minutes before the phones officially went on sale. 

The Apple store on the Upper West Side in Manhattan sold out of the iPhone 6 Plus, even as a line for reservations spilled into a concert hall next door and a regular line snaked up two blocks.

Even before the first day of sales, there were signs that supply of the new device may not meet demand. During the first 24 hours of record pre-orders a week ago, the iPhone 6 Plus, which has a larger display, started having shipping delays of three to four weeks, while some iPhone 6 models faced delays of seven to 10 days.

In Portland, Cory Nguyen, a 19-year-old college student, said he was planning to get an iPhone 6 Plus until he heard employees tell people in line that they had run out of the bigger device. He?s instead settling for two iPhone 6 models that he plans to resell.

"I know people," Nguyen said. "Everyone wants an iPhone. It’s high demand. It’s extra cash."

Carl Howe, an analyst at 451 Research LLC, said Apple may sell 12 million to 15 million new devices this weekend. Toni Sacconaghi, an analyst at Sanford C. Bernstein & Co., wrote in a note to investors that he?s projecting sales of 7 million to 8 million, which would fall short of last year’s first weekend sales of 9 million units of the iPhone 5s and 5c. Sacconaghi attributed it partly to supply constraints and to the fact that China isn’t one of the first countries selling the devices.

A Sprint Corp. store at 42nd Street in Manhattan had no iPhone 6 Plus devices as of 8:30 a.m. New York time, and the AT&T Inc. store at 46th Street and Madison Avenue was sold out of the model. An employee outside the AT&T store said they started with only a couple and were telling customers they could place orders for November delivery.

Apple’s iPhone rollout is the most important event this year for the Cupertino, California-based company. Chief Executive Officer Tim Cook is counting on the handsets to maintain Apple’s sales growth. The devices generate more than half of the company?s annual $171 billion in revenue and precede a swath of other products, including new iPads and Apple Watch. The iPhones have screens of 4.7 inches and 5.5 inches, compared with 4 inches for previous models — helping Apple appeal to new consumers.

More than 1,000 people were in line for Apple’s Regent Street store in London, some sitting on pieces of cardboard to stay dry after a night of rain. Llewellen Fourie, a surveyor from London, said he?s had an iPhone since the original came out, and is now looking to upgrade his golden iPhone 5 to the 6 Plus because of its larger screen.

"Anything new is exciting even if it’s a paint job," said Fourie, 39.

The line of hundreds of people outside the Apple store in central Sydney snaked around the block, then down a parallel street before extending three more blocks. At the middle of the line, Xin Liu, 25, a student at the Sydney Institute of Interpreting and Translating, had waited more than 11 hours to buy her parents a new phone.

"When I came here, I thought there would be about 500 people," she said. "But someone counted and there were already 800. I was really surprised."

In Hong Kong, hundreds lined up at the Apple store at the IFC mall to collect their new iPhones after registering online in advance. They were met by about a dozen protesters from Students and Scholars Against Corporate Misbehaviour holding up signs that said "iSlave 6. Still made in sweatshops" and "Throw Away the Bad Apple."

With Apple yet to say when the iPhone 6 will be available in China, Chen Daihui and Yao Haitao traveled from the mainland to Hong Kong to try to secure the devices. After failing to register online, they were both disappointed.

"All I wanted was to go inside and have a look, and they wouldn’t let me do that," said the 32-year-old Chen, who traveled from Fujian. "Looks like I will just have to wait."

The Apple store in Tokyo’s Shibuya area had about 600 people lined up an hour before opening, while the one in nearby Omotesando had about 1,000. They included a woman near the front of the line wearing a Steve Jobs mask, carrying a red apple.

"The most important aspect of first weekend iPhone sales are the long lines and the record breaking sales numbers that generate the free press for the company," Walter Piecyk, an analyst at BTIG LLC, wrote in a note to investors yesterday.