New Delhi, March 21 -- After a four-year break, K-pop supergroup BTS returns Saturday with a massive, free comeback concert in Seoul, where thousands of police are locking down a central boulevard for the Netflix-exclusive spectacle expected to draw tens of thousands of fans.

The performance at Gwanghwamun Square launches a monthslong global tour spanning dozens of shows across the United States, Europe and Asia.

All seven members of the band - RM, Jin, Suga, J-Hope, Jimin, V and Jung Kook - recently completed South Korea's mandatory military service, and hope to reclaim their status as one of the world's biggest pop acts.

The hourlong concert comes a day after the group released its fifth album, "ARIRANG," which had already logged sev...