RIYADH — Dozens of Saudi families flocked to the movies on Friday for the first time in almost 40 years, two days after US movie giant AMC unveiled the Kingdom’s debut theater in Riyadh.

Tickets for the American superhero movie “Black Panther”went on sale online at midnight for SR75 ($20) and sold out within minutes. Excited cinemagoers posed for selfies in the foyer and stood in line for popcorn.

“It’s like a historical event that happened here,”said Mana, an usher at the movie theater in the King Abdullah Financial District, a new development in northern Riyadh.

Before the main feature, the audience watched a short on the history of film, a clip from a US television interview with Crown Prince Muhammad Bin Salman, and an advertisement for Coca-Cola featuring women driving.

The choice of movie was not random.

“It is the story of a young prince who transforms a great nation,”Adam Aron, chief executive of the theater operator AMC Entertainment Holding said at a VIP screening on Wednesday. “That might sound familiar to a few of you.”

To serve a population of more than 32 million, most of whom are under the age of 30, the authorities plan to set up around 350 cinemas with over 2,500 screens by 2030, which they hope will attract nearly $1 billion in annual ticket sales.

An AMC official said the movie chain could possibly release the much-anticipated thriller “Avengers: Infinity War” at the cinema next week, around the same time as its global release.

International theater chains have long eyed Saudi Arabia with its more than 30 million people as the Middle East’s last untapped mass market, the majority of whom are under 25.

AMC will face stiff competition from heavyweights such as Dubai-based VOX Cinemas, which on Thursday announced it had also secured a government license to operate in Saudi Arabia and would open the Kingdom’s first IMAX theater in the coming days. — Agencies