The nominee pool won't be the only thing lacking racial diversity at the Oscars this weekend. The red carpet at the Dolby Theatre in Los Angeles will be missing a few of Hollywood’s biggest black stars and directors, too.

Several of them are scheduled to attend an event that would benefit the largely black and poor residents affected by the water crisis in Flint, Michigan, according to the Washington Post. But while some stars say the scheduling of the Flint event was a coincidence, many of those not attending the ceremony were also outspoken when this year’s nominations revealed an all-white slate in the acting categories, for the second year in a row.

Among those snubbing the Oscars this year is film director Ava DuVernay, who in 2015 became the first black woman nominated in the best director category of the Golden Globes, for the Martin Luther King Jr. biopic “Selma.” She’s been announced as a featured guest at #JusticeForFlint, a free event promoting solidarity with Flint residents affected by the dangerously high lead contamination in the city's water supply.

DuVernay will be joined by “Creed” director Ryan Coogler, whose boxing drama was snubbed in every category except supporting actor, with a nomination for Sylvester Stallone. Singer Janelle Monae, a regular on Hollywood red carpets, is also expected to attended the Flint event.

Coogler told BuzzFeed News that the timing of the Michigan event was set to coincide with Black History Month, and was not an explicit Oscar snub. But actress Jada Pinkett-Smith; her husband, Will Smith; and film director Spike Lee are among the black Hollywood stars who said they would intentionally skip Sunday’s Oscars ceremony over the diversity issue. The civil rights community will be involved, too.

Rev. Al Sharpton is expected to headline a national Academy Awards ceremony tune-out rally in Hollywood in conjunction with his National Action Network, a civil rights group. The New York-based organization has planned a handful of rallies to take place simultaneously in cities such as Cleveland, Miami and Detroit.

CORRECTION: A previous version of this article incorrectly stated the award nomination that Ava DuVernay received for the film "Selma." The text has been updated to reflect this correction.