A woman stabbed and seriously injured her 16-year-old son this morning in Frankford, police said.

The woman is in custody but has not been charged yet.

The circumstances surrounding the stabbing on the 1200 block of Pratt Street also are unclear.

Police said the woman stabbed the boy in the rib cage, right arm and right ear.

He was taken to Aria Health's Torresdale campus in serious condition, police said.