Ariana Grande's mother ushered fans to safety after explosion at concert

— -- Moments after the explosion at an Ariana Grande concert in Manchester, England, on Monday night, the singer's mother, Joan Grande, went into action and helped usher a number of fans backstage, ABC News has confirmed.

Joan Grande was already heading backstage to see her daughter when she heard the explosion, which is being treated as a terror attack. Grande's mother was then able to help get the fans to safety, TMZ was first to report.

After Monday's night's attack, which left 22 dead, it's not clear what Ariana Grande will do about the rest of her tour, which was set to resume on Thursday.

The singer tweeted last night that she was "broken."

"From the bottom of my heart, i am so so sorry. i don't have words," she wrote.

Among those killed in the "sickening" attack, as it has been called by United Kingdom Prime Minister Theresa May, were two young girls, ages 8 and 16. More than 50 others are injured.

Celebrities including Miley Cyrus and Taylor Swift have shared their support for the victims and for Ariana Grande.

"Wishing I could give my friend @arianagrande a great big hug right now... love love love you ... my most sincere condolences to anyone and everyone affected by this horrific attack! all I can do is send as much HOPE & PEACE your way!" Cyrus wrote on Instagram.

"My thoughts, prayers and tears for all those affected by the Manchester tragedy tonight. I'm sending all my love," Swift said.