Rolling Protest with Orange and Yellow Flags

I just watched about 50-100 cars roll down Westheimer with orange and yellow flags honking their horns and yelling things. I couldn't hear what they were yelling or see any sign text from my apartment balcony.

Anyone know what these guys are on about?

EDIT: Thanks for those who responded. This protest is apparently to bring attention to the massive humanitarian crisis in the Tigray region of Ethiopia happening now. Here's the wiki entry: https://en.wikipedia.org/wiki/Tigray_War