Democratic presidential candidate Sen. Bernie Sanders of Vermont is making a personal appeal to supporters in the wake of the massacre of nine people at the historically black Emanuel African Methodist Episcopal Church in Charleston, South Carolina.

In an official email release from his campaign on Thursday, Sanders asked for donations for the church and explicitly referenced the apparent racial nature of the killings.

“Nine of our fellow Americans were murdered while praying in a historic church because of the color of their skin. This senseless violence fills me with outrage, disgust, and a deep, deep sadness,” Sanders said in the email. “This hateful killing is a horrific reminder that, while we have made important progress in civil rights for all of our people, we are far from eradicating racism.”

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Besides Texas Sen. Ted Cruz, most of Sanders’ 2016 rivals have shied away from linking race to the tragedy in Charleston. The prime suspect in the shooting, Dylann Storm Roof, a 21-year-old white man, is currently in police custody, but little is known about his alleged motives.

In his email, Sanders made highlighted the historic importance of Emanuel AME Church.

“The Emanuel African Methodist Episcopal Church is one that has been attacked, burned, and rebuilt throughout its 200 year history. While their community mourns now, they will rebuild, and they will emerge stronger than before,” he wrote.

“Let us stand with them in their time of mourning,” he added.

Sanders had received some criticism for holding a rally about pensions on Thursday not far from the site of prayer vigil for victims of the shooting, but he has also been applauded for his direct appeal on the church’s behalf.