Hundreds of people flocked to the annual book fair in Wan Chai early on Wednesday, some bringing suitcases along with them for the shopping sprees they were about to embark on.

This year's Hong Kong Book Fair, which is themed on children's and young adult literature, attracted a crowd even before the doors opened at 10am.

Among the early birds was a man surnamed To – the first in the queue at the exhibition and convention centre – who had arrived at around midnight.

To said he hoped to get a signed copy of a book by a local novelist.

Some teenagers at the fair said they had school on their minds when looking for books.

"I aim to buy textbooks, because at the book fair, there are a lot of publishers and I hope that I can buy textbooks earlier and do some revision earlier," a 16-year-old told RTHK.

A 15-year-old said she was looking for novels to buy with vouchers she got for school book reports.

The fair has attracted vendors from outside the SAR, including a publishing company based in San Diego in the United States.

James Dodge Perez from ReadersMagnet told RTHK the company is "so proud and elated" to be part of the week-long event.

"This is basically the first time that we have joined a book fair in Asia...Undoubtedly Hong Kong is the biggest market in Asia, and it's a gateway to Asia," he said.

"Compared to events we participated in the US for the past years, this is the very first time that it's a week-long event. Usually we do it on a weekend, from Fridays to Sundays. But this time, we are joining Wednesday to Tuesday until next week. We are happy about that."

Political titles removed from public library shelves are on sale at the fair. One publisher selling such publications said no one had stepped in to stop them.

"Everyone had been asking about this since last year, and actually we are not too worried, because the government has said people can still purchase titles at book stores, and we have all along been selling these books," he said.

An adult ticket costs HK$30, while admission for children is HK$10. Entry is free for those who are three years old or younger, as well as people aged 65 or above.

The book fair lasts for a week until July 25 and runs concurrently with a sports and leisure exhibition as well as a snacks fair.