A rep for the band tells us, "It is with great sadness that we report the passing of Wayne Swinny, the guitarist of Saliva. Wayne passed away this afternoon from a spontaneous brain hemorrhage while on tour."

The tragic news comes only hours after the band revealed Wayne was in the ICU after having the medical emergency.

Bobby Amaru, Saliva's lead singer, says, "I’m not even sure what to think or how to feel right now. My heart aches for Wayne’s family, his friends, and anyone who had the joy of being around him. My heart aches for his daughter Nikki. He loved that little girl so much ... He would go out of his way to make sure you had a good time. I’m grateful that I got to share almost 12 years of my life with Wayne on the stage and most importantly off the stage."

Amaru continues, "He was the older brother I never had. I learned so much from him and we had a f***ing blast together! I will cherish it all for the rest of my life! God Bless you Wayne. I know we’ll meet again!!"

As we reported ... Wayne had been battling for his life in the ICU. He was rushed to a hospital Tuesday and diagnosed with a spontaneous hemorrhage in his brain.

Wayne was one of Saliva's founding members, helping to start the band way back in 1996.

The wife of Saliva's former lead singer, Josey Scott, also posted about Wayne's death, saying the band is in "complete shock and heartbreak."

She says Josey referred to Wayne as his "musical soulmate" and she's remembering him for having a great sense of humor.

Wayne was 59.