MEXICO CITY, MEXICO (AP) — Thousands of “tween” girls jammed a vast square with their parents and screamed in unison throughout teen superstar Justin Bieber’s free concert Monday night, an event that was expected to draw 200,000 people to the historic centre of Mexico’s capital.

Bieber opened with his hit song Baby, while his adoring fans filling the city’s main plaza sang along or shouted “Justin! Justin! Justin!”

“Mexico City, there is a lot of people today!” Bieber told the crowd. “Every one of you is my biggest fan.”

Dressed in white jeans and a grey sweatshirt that he took off to reveal a white T-shirt, the singer wore neon yellow tennis shoes and was accompanied by five dancers in neon colours. Four giant screens showed parts of his music videos to the crowd of mainly girls and their parents, who braved a light, intermittent rain during the concert.

The crowd went wild when Bieber asked a fan onto the stage, gave her a bouquet of flowers and sang One Less Lonely Girl into her ear. The girl didn’t stop crying.

The grey and reddish stones of the plaza were covered in a sea of purple as the mainly 10- to 14-year-old crowd paid homage to what is reported to be Bieber’s favorite colour.