Prosecutors on Thursday added four charges of lewd conduct against a father accused of torturing his children in a Northern California home where prosecutors say 10 children lived in filth and neglect.

The charges against the 29-year-old man were filed as he and his 31-year-old wife appeared in Solano County Superior Court.

The father faces nine counts of felony child abuse, seven counts of felony torture and four counts of lewd conduct on a child under 14.

The mother faces nine counts of felony child abuse and one count of child neglect involving all 10 children. Both have pleaded not guilty.

Prosecutors say the children were punched, kicked, strangled, shot with a BB gun and subjected to waterboarding by their father, while their mother did nothing to stop it.

The Associated Press is not naming the parents to protect the identity of the children, in line with AP's policy to avoid identifying victims of alleged sexual abuse.

Records show the 10 children removed from the house on March 31 are 6 months to 12 years old,

Documents filed in the case do not specify the injuries sustained by each child.

Prosecutors have not elaborated on the case since announcing last week that they had removed the children from the home where they say torture was carried out "for sadistic purposes."

Fairfield police found the children huddled on the living room floor of the two-story home that was littered with feces and trash in the suburb 46 miles (74 kilometers) northeast of San Francisco, prosecutors said.

"The children appeared to be skittish and spoke with speech impediments," prosecutor Veronica Juarez wrote in a request last week to raise the father's bail to $5.2 million.