A Florida man convicted of murdering two women in 1996 was executed by lethal injection on Tuesday, local media said.

Michael Zack, 54, was put to death at the Florida State Prison in the town of Raiford, the Pensacola News Journal reported.

The newspaper said the lethal drug cocktail was administered at 6:02 p.m. and Zack was pronounced dead 12 minutes later.

Zack was sentenced to death in 1997 for the June 1996 sexual assault, robbery, and murder of Ravonne Smith, a woman he met at a bar.

He was also convicted of the murder of another woman, Laura Rosillo, who had befriended him at another bar.

Zack's defense attorneys had sought to block his execution on the grounds that he suffered from fetal alcohol syndrome and was intellectually disabled.

His appeals were denied by lower courts and eventually the Supreme Court.

The group Floridians for Alternatives to the Death Penalty released a final statement from Zack.

"Twenty-seven years ago, I was an alcoholic and a drug addict," it said. "I did things that have hurt a lot of people — not only the victims and their families and friends, but my own family and friends as well.

"I have woken up every single day since then filled with remorse."

There have been six executions in Florida this year and 19 in the United States.