Updated

Nearly 30 Africa-based rights groups have signed a letter condemning Sudan for sentencing a 20-year-old woman to death by stoning over charges of adultery.

The statement, signed and released Friday, is urging Sudanese authorities to cancel the sentence passed May 13 and release Intisar Sharif Abdallah.

Rights groups are concerned that Sudan is leaning toward the application of a strict interpretation of Shariah, or Islamic law.

Abdallah is being held in a prison in Sudan's capital of Khartoum with her 4-month-old baby.

The rights groups say she initially pleaded not guilty to the adultery charges, but later admitted to them after beatings from her brother. Then she was subjected to what they called an "unfair trial."

Rights lawyers have filed an appeal for her.