M11

This stamp was issued by Correos on 11 March 2024 to commemorate (?) the 20th anniversary of a terrorist attack in Madrid. As you can read in Correos website:

[...] Twenty years later, it is important to remember and honour the victims, as well as reflect on the legacy of this tragic event. The collective memory of those dark days should serve as a reminder of the fragility of peace and the importance of solidarity and unity in times of crisis, something that should strengthen the social fabric that unites us as a society. [...]

It seems to me, however, an odd and sad issue.