In this clip, we can see the shockwave from the same explosion spreading over the water.
The cause of the explosion can be found here:
Confiscated sodium nitrate.
https://twitter.com/ragipsoylu/status/1290698269421600770?s=21 https://twitter.com/ragipsoylu/status/1290698269421600770
Confiscated sodium nitrate.
https://twitter.com/ragipsoylu/status/1290698269421600770?s=21 https://twitter.com/ragipsoylu/status/1290698269421600770
Another angle: