The flag is a plain field (in many different color variants) with the municipality coat of arms, consisting of checkered red and green and a phoenix (representing the many rebirths of the city along the history). Here's my proposal:
The red and green lozenges are intercalary with white ones, representing the peace and the future to be written. I don't know if a flag based on a municipality's is adequate, but this design is, for sure, striking.
Your comments are welcome.
But, please, don't forget that the this isn't a post about politics or so, but only vexillology.