A blast at an Ariana Grande concert in the northern English city of Manchester has killed at least 19 people and wounded 50 others, with police calling it a "terrorist incident".

If confirmed, it would be the deadliest attack in Britain since four men killed 52 people in suicide bombings on London's transport system in July 2005.

A spokesman for the American pop star said the singer was "OK". Soon after the incident, Grande tweeted that she was left emotionally “broken”.

Al Jazeera's Alexi O'Brien reports.

manchester arena attack location map infographic

Europe, United Kingdom