Tommy Lee allegedly assaulted by 21-year-old son over Pamela Anderson tweets

The alleged fight between Tommy Lee and his 21-year-old son Brandon reportedly started after the rocker sent out several controversial tweets about his ex-wife -- and Brandon's mother -- Pamela Anderson.

The former Motley Crue drummer was reportedly attacked by his son in a drunken brawl, according to multiple reports.

The Los Angeles County Sheriff Department told People officers responded to an incident at Lee’s home on Monday evening where they found the 55-year-old with a bloody lip. Brandon was not at the scene when police arrived and has not yet been arrested, according to the mag.

"My fiancee and I were in bed when my son busted into the room and assaulted me,” the rocker tweeted Tuesday night. “I asked him to leave the house and he knocked me unconscious. He ran away from the police. THAT’S the truth.”

PHOTO: Click here to see Tommy Lee's bloodied face

Lee also posted a picture of his bloodied lip but later deleted it. He had captioned the photo, "My heart is broken. You can give your kids everything they could ever want in their entire lives and they can still turn against you."

The alleged tussle was reportedly started after Brandon saw his father's tweets about his mom Anderson. Lee and Anderson had an on-and-off again relationship for many years and share two sons together, Brandon and Dylan.

In 1998, Lee was sentenced to six months in jail on domestic violence charges stemming from an incident with Anderson.

“Think she’d find something new to discuss instead of rehashing old s— but I guess she has nothing else going on & needs attention Signed, ‘The abuser’ (who she texts every day & asks for me back),” Lee tweeted on March 5 in reference to his ex.

Brandon spoke out in a video on Instagram Story according to People. "As I get older, I have started to realize that there are very few people you can trust … that’s my super depressing thought for tonight. Just thought I’d share it and be a d—,” he said.

Lee's fiancee, social media sensation Brittany Furlan, tweeted on Tuesday, "Violence is NEVER the answer."