After donating money to the victims of Hurricane Harvey, Philadelphia-born comedian Kevin Hart is calling for other Hollywood stars to do the same.

Hart, who has reportedly pledged $25,000 to the Red Cross for Harvey relief efforts, posted an Instagram video on Sunday explaining that he was starting a celebrity challenge centered on donating money to victims. Hart specifically named a number of celebrities in the video whom he challenged to donate money, including Jerry Seinfeld, Dwayne Johnson, and Justin Timberlake.

Harvey hit land on Friday, moving into Texas as a category 4 hurricane, according to ABC.

During a news conference on Monday, Houston Mayor Sylvester Turner addressed Hart's charity, and thanked the star for his support.

"I want to thank people like Kevin Hart, who's already indicating and asking people to give," Turner said.

The Red Cross issued a statement over the weekend that "shelters are open, truckloads of supplies are being distributed and volunteers [are] in place" across the Gulf Coast as a result of the damage in Harvey's wake.

Hart is not the only star to lend a hand to Harvey victims. Singer Chris Young donated $100,000 to a GoFundMe campaign he started that is aimed at benefiting the Red Cross, according to the Hollywood Reporter. Others have voiced their support on social media, including Beyoncé and Miranda Lambert, both of whom are Texas natives:

Athletes are also getting in on the giving action. Houston Texans defensive end JJ Watt set up a relief fund-raiser that had $726,000 in donations by Monday evening, including $100,000 from Watt. His goal is $1 million.

According to CBS, officials expect floodwaters to rise for several more days in areas effected by Harvey. About 450,000 people are expected to file for disaster assistance, FEMA Administrator Brock Long recently told reporters.