Nine people were gunned down in Dylann Roof's alleged hate crime at a historic black church in Charleston, South Carolina on Wednesday night (17Jun15) and the tragedy sent shockwaves through America and beyond, prompting stars including Chris Pratt, Patricia Arquette, Mandy Moore, Kerry Washington, John Legend, Beyonce, and Tyler Perry to express their views on social media and offer up prayers to the families of those killed.

Beyonce's husband, Jay Z, kept the victims in his thoughts on Sunday as he marked Father's Day with the couple's daughter, Blue, by taking to Twitter.com to write, "Love to all the beautiful souls lost in the Emmanuel Church. Special Father's Day prayers to those who lost their dad."

Footloose star Bacon also honoured those murdered in Charleston, adding, "On this #FathersDay my heart goes out to those children who lost fathers and mothers in this terrible act of hate #EmanuelAMEChurch".

Meanwhile, other stars flooded the microblogging site to celebrate their dads on the international holiday, with Justin Bieber tweeting, "Happy Father's Day @JeremyBieber I love you", and pregnant actress Naya Rivera giving a shout-out to her husband, actor Ryan Dorsey, as the couple prepares to welcome its first child. She writes, "happy Father's Day to the best dad to be in the world @DorseyRyan! I'm so proud to give you a child. Love you!"

Mark Ruffalo posts, "Happy #FathersDay Frank Ruffalo! You are the greatest Dad. Thanks for all your love and kindness", while singer Nick Lachey adds, "To all the proud dads out there, a very Happy Fathers Day!! There is truly nothing like being a father. #HappyFathersDay", and Kelly Osbourne pays tribute to her rocker father Ozzy, stating, "Happy Fathers Day Dadda! I'm one of the luckiest girls in the world!!! (Not) only are you my dad but you're also my best friend and my hero!!!"