The arrests happened in Uppsala, north of Stockholm, on Sunday, after members of an online group raised the alarm. The alleged attack was streamed by a group which has 60,000 members. The video has been removed from Facebook but is understood to have been seen widely. Facebook specified it always co-operates with police in criminal investigations. The suspects will be charged by aggravated rape. Police said the 24-year-old suspect is a repeat offender and considered to be the main attacker. Facebook started offering live-streaming features at the end of 2015. Live videos can be reported to a team, which is on call 24 hours a day. Reviewers in the team can interrupt a live stream if it breaches Facebook’s community standards.