About 20 police are investigating the second case of suspected child abuse in Northland in less than a week.

Seventeen-month-old Tinisha Walker was seriously injured at a house in the suburb of Kamo, 5km north of central Whangarei, on Tuesday.

Whangarei St John district operations manager Doug Gallagher said the child was taken to Whangarei Hospital by ambulance at 1.15pm.

She was flown by the Northland Electricity Rescue Helicopter at 2.45pm to Auckland's Starship hospital.

She was still in a critical but stable condition last night, a hospital spokeswoman said.

Police last night remained silent on the investigation.

Inspector Marty Ruth of the Whangarei CIB said, "Things are progressing nicely and we hope to have some good news for the general public in the morning".

He would not comment on whether the child's parents had been allowed to visit her in hospital.

Child Youth and Family Services would not confirm whether it was involved.

"Because this matter is the subject of a current police investigation [CYFS] is unable to comment so as not to compromise that process," said Marion Heeney, CYF northern regional director.

The incident follows the death of a 2-year-old Kaitaia girl.

The child died in Starship on Saturday morning,

Her 34-year-old mother has been charged with assault.

* Northland abuse

Tuesday: A 17-month-old Whangarei girl is flown to Starship hospital with serious injuries. Police are speaking with her family.

Saturday: A 2-year-old Kaitaia girl dies in Starship. Her 34-year-old mother is charged with assault.

December 23, 2008: 16-month-old Riley Justin Osborne of Kerikeri dies in Starship from head injuries. His stepfather Kyle Skerten, 22, is to stand trial for his murder in September.