At least 50 people have been killed and dozens injured after a gunman opened fire at a gay nightclub in Orlando, in an incident that lasted three hours. What do we know about what happened?

How the incident unfolded

The attack began at about 02:00 local time (06:00 GMT), said Police Chief John Mina.
Pulse, which is one of the biggest nightclubs in Orlando, Florida, was holding a Latin-themed event that was nearing its end when a man opened fire inside.
Shortly afterwards, the nightclub posted on its Facebook page: "Everyone get out of pulse and keep running."