Brain aneurysm

BBC reports Sizemore found fame in the 1990s, often playing supporting roles as tough guys - usually military, police or criminal. His other credits included Natural Born Killers, Pearl Harbor and Heat.

But he also had drug problems and served jail time for domestic violence.

Sizemore had been in a coma since suffering a ruptured brain aneurysm on 18 February.

"He is currently in critical condition and it's a wait and see situation," the 61-year-old actor's manager, Charles Lago, wrote in an email.

Reuters reports Sizemore, whose film and television career has spanned decades, is best recognized for his roles as the battle-hardened sergeant at Tom Hanks' side in the 1998 film Saving Private Ryan and as commander of an Army Ranger battalion in 2001s Black Hawk Down. He was nominated for a Golden Globe Award in 2000 for best actor in a miniseries or film made for television for his role in Witness Protection.

The 55-year-old was taken to Cedars-Sinai Medical Center in Los Angeles on Monday, TMZ reported.

In a post on Instagram, he said: "I'm doing great and getting excellent care from my medical team."

He is "resting comfortably" after the aneurysm, his lawyer told Billboard.

In his post, Dr Dre also wrote: "I will be out of the hospital and back home soon. Shout out to all the great medical professionals at Cedars. One Love!!"

Friends and fellow stars have sent their well wishes after the reports of his ill health emerged.