17 people dead

Fourteen other people, including the groom, were injured. The bride was not with the wedding party.

The party was disembarking from a boat at the riverside town of Shibganj, heading towards the bride's house, when they were caught in a thunderstorm.

Local people said several bolts of lightning hit the group.

Every year, hundreds of people across South Asia are killed by lightning.

In 2016, Bangladesh declared lightning strikes a natural disaster when more than 200 people died in the month of May alone, including 82 people on a single day.

The suspect has been named as Nikolas Cruz, 19, and is a former student at the school who had been expelled.

As the attack unfolded students were forced to hide as police swooped in on the building.

It is one of the deadliest school shootings since 26 people were killed at a Connecticut school in 2012.

Broward County Sheriff Scott Israel told reporters Cruz killed three people outside the school, before entering the building and killing another 12.

Two people later died after being taken to hospital.