The violence is abhorrent. But it was inevitable. The violence didn't exist in a vacuum, all the conditions and suffering so many were put through birthed it.
The opposition say Eritrean government officials who are responsible for the calamity, should not be able to collect money from communities abroad. And some European governments have agreed and decided to revoke permits for regime festivals.
The German city of Stuttgart did so after violence last year.
https://www.dw.com/en/germany-dozens-injured-in-unrest-at-eritrean-event/a-66837449