Beyonce, one of the most famous natives of Houston, has pledged generous but unspecified aid after the fourth most populous US city was ravaged by mega-storm Harvey.

The pop superstar, in a statement to the Houston Chronicle, said she was working out details with her team and her Houston pastor "to implement a plan to help as many as we can."

Beyonce -- whose net worth with her husband, rap mogul Jay-Z, is estimated at $1 billion -- said that Texas was "in my prayers" in a post to her more than 100 million followers on Instagram.

Elsewhere in the music world, leading rapper Drake -- a Toronto native who keeps a home in Houston -- said he was "working with local relief groups to aid and assist the people of Texas in any way we can and in the most immediate way possible."

"I encourage everyone to do what they can to assist the people of Texas knowing whatever effort you can make to help will go a long way," Drake wrote on Instagram.

Among more specific commitments, comedian Kevin Hart said he was donating $25,000 to the American Red Cross for relief in Houston and urged other stars -- a few of whom, including Beyonce and Jay-Z, he named -- to do the same.

"I am challenging a lot of my celebrity friends to follow my lead in donating $25,000," Hart said.

"I think that people are in bad shape and need help, and I'm going to lead the charge," he said.