Tributes continued to pour in on Sunday in for Malcolm Young, co-founder of the Australian rock band AC/DC, a day after he died at age 64 after suffering from dementia for several years.

Malcolm Young and his brother Angus Young founded AC/DC, whose hits included "Highway to Hell" from 1979 and "Back in Black" and "You Shook Me All Night Long" from 1980.

"Malcolm, along with Angus, was the founder and creator of AC/DC. With enormous dedication and commitment he was the driving force behind the band," AC/DC posted on its Facebook page on Saturday night. Young was a songwriter, backing vocalist and rhythm guitarist for AC/DC, a hard rock and heavy metal band that was inducted into the Rock & Roll Hall of Fame in 2003.

By Sunday morning, fans and friends had posted 56,000 comments on Facebook under the band's announcement

Giants of the music world took to social media to express their shock. Other rockers paid tribute to Young's lasting influence.

Ozzy Osborn tweeted that it was "so sad to learn of the passing of yet another friend, Malcolm Young", and Eddie Van Halen tweeted that it was a "a sad day in rock and roll".

"Malcolm Young was my friend and the heart and soul of AC/DC. I had some of the best times of my life with him on our 1984 European tour. He will be missed and my deepest condolences to his family, bandmates and friends."

Kiss bassist Gene Simmons added to the condolences, tweeting: "Malcolm was a good man. Always a kind hearted soul. finally recall when we took out AC/DC on their first American tour. It (sic) will be sadly missed. RIP".

Young is survived by his wife O'Linda, children Cara and Ross, three grandchildren, a sister and a brother, the band said. He "passed away peacefully with his family by his bedside," the band stated.

Young's family confirmed in 2014 that he was suffering from dementia. Young last performed with the band in 2014, then stepped aside for his nephew, Stevie, to take over rhythm guitar duties for the band's last tour to promote its 2014 album, Rock Or Bust.

AC/DC has sold more than 200 million albums across the world.

George Young, another brother to Malcolm and Angus, died on Oct. 23 at age 70. George Young had served as producer to AC/DC and guitarist for the band Easybeats.

(Reporting by Alana Schetzer, Daniel Trotta; Editing by David Gregorio) ((alana.schetzer@thomsonreuters.com;))