A man accused of holding three women captive for about a decade in the United States has pleaded not guilty to hundreds of charges, including rape and kidnapping.

Ariel Castro, 52, had been charged with kidnapping the three women and keeping them along with a six-year-old girl he fathered with one of them.

Amanda Berry, Gina DeJesus and Michelle Knight disappeared separately in the Cleveland area of Ohio between 2002 and 2004, when they were 14, 16 and 20 years old.

Mr Castro was arrested on 6 May, shortly after Ms Berry broke through a door and yelled to neighbours for help.

A grand jury charged Mr Castro with two counts of aggravated murder for allegedly causing the unlawful termination of one of the women's pregnancies.

He also was indicted on 139 counts of rape, 177 counts of kidnapping, seven counts of gross sexual imposition, three counts of felonious assault and one count of possession of criminal tools.

More charges could yet be filed as a 142-page indictment only covers the period from August 2002 to February 2007.

Prosecutors say the investigation will continue and they are leaving the door open to pursuing a death penalty case against Mr Castro.

The indictment against Mr Castro alleges he repeatedly restrained the women, sometimes chaining them to a pole in a basement, to a bedroom heater or inside a van.

It says one of the women tried to escape and he assaulted her with a cord around her neck.

Later, he moved them to upstairs rooms where they were kept as virtual prisoners, according to investigators.

All the time, Mr Castro continued driving a school bus and playing bass in local bands.

He was fired as a bus driver last year after leaving his bus unattended for several hours.

Mr Castro has been held on $8m bail.