RIO DE JANEIRO: Five armed men stormed into a youth hostel early Sunday and robbed some 20 tourists, mainly Brazilians, near the site of Rock in Rio, the music mega-festival under way here, police said.

“I still haven't had time to count how many people were robbed because I'm still so shaken up, but they (the assailants) didn't touch the foreigners. They only robbed the Brazilians,” the proprietor of the hostel in the popular tourist area of Copacabana said on Globo's website G1.

Police in a statement said they were looking at video from security cameras in and around the property for details.

Thousands of Brazilians and international visitors have converged on Rio as the music festival returned to the city of its origins for the first time in a decade. Rock in Rio kicked off Friday with an all-star line-up including Rihanna, Katy Perry and Elton John.

The event is expected to attract 700,000 people over its week-long run, with around 100,000 a day turning out to see some of the biggest names in music belting out tunes on Rio de Janeiro's shores.