By Kim Palmer

CLEVELAND (Reuters) - Former Cleveland school bus driver Ariel Castro faces 977 criminal charges stemming from the abduction and decade-long imprisonment of three women who were freed two months ago, as 648 new charges were added on Friday, prosecutors said.

A grand jury's indictment spans from August 2002, when Castro was accused of abducting the first of the women, through May of this year when the women and a 6-year-old girl fathered during her mother's captivity escaped his Cleveland home.

"Today's indictment moves us closer to resolution of this gruesome case," Cuyahoga County Prosecutor Timothy McGinty said in a statement.

Fired last fall from his job as a Cleveland school bus driver, Castro stands accused of kidnapping the three women between 2002 and 2004 and brutalizing them while holding them captive in his house over the next 10 years.

Castro, who turned 53 on Wednesday in jail, was indicted in June on 329 charges involving the first 4-1/2 years of the women's captivity. They and the girl were freed from his house on May 6.

Gina DeJesus, 23, Michelle Knight, 32, and Amanda Berry, 27, had been missing for around a decade. Officials said they were kept bound for periods of time in chains or rope and that they endured starvation, beatings and sexual assaults. ?

DNA evidence later confirmed Castro was the father of the girl, who was born to Berry. At a court appearance in early July, Castro asked to be allowed jail visits from his daughter. A judge rejected the request immediately as "not appropriate."

Three of the new charges involve endangering a child and a another was a felony kidnapping for the 6 years since the girl's birth.

Berry, DeJesus and Knight spoke publicly for the first time since they were freed in videotaped statements released on Tuesday that thanked people for their emotional and financial support.

'THROUGH HELL AND BACK'

"I may have been through hell and back, but I'm strong enough to walk through hell with a smile on my face, and with my head held high, and my feet firmly on the ground," said Knight, who Castro is accused of beating to induce miscarriages.

A representative for the women said they would not comment on the new indictment.

In a statement, Castro's attorney, Craig Weintraub, said the additional charges had been expected.

"It is our hope that we can continue to work toward a resolution of this matter so that the women do not have to endure any additional trauma," he said.

Castro faces aggravated murder charges under a fetal homicide law for allegedly forcing Knight to miscarry. According to the indictment, Knight was pregnant at least three times from September 2002 to December 2003.

Aggravated murder charges qualify the case for the death penalty, but the prosecutor's office has not yet decided whether to seek that punishment.

The indictment also includes 512 counts of kidnapping, 446 counts of rape, seven counts of gross sexual imposition, six counts of felony assault, and one count of possessing tools such as a Ruger handgun.

The latest indictment adds rape, kidnapping and felonious assault charges for every month the women were in captivity and included specific dates throughout their captivity.

Castro will be arraigned July 17 on the new indictment before Common Pleas Court Judge Michael Russo. He is being held on an $8 million bond. Trial is scheduled to begin on August 5.

(Editing by Richard Chang)