Police in northern China have launched a massive search for a woman accused of gouging out the eyes of a six-year-old boy.

Authorities in the city of Linfen in Shanxi province on Wednesday offered a $16,000 reward for the woman's capture.

We are sparing no efforts trying to solve this case Liu, Chinese police officer

Police did not say if they had identified a suspect, and the boy said only that the woman spoke with an accent from outside the area.

State media said the boy was recovering in a hospital, but had lost his sight permanently following the brutal ordeal on Saturday.

A police officer who only gave his surname, Liu, said he could not speculate on a motive because the investigation was continuing.

"We are sparing no efforts trying to solve this case," he added.

Liu said the boy's eyeballs were found at the scene, and that the corneas had not been removed.

State media previously had raised the possibility that the boy's corneas were taken for sale because of a donor shortage in China.

A news report on a provincial TV channel showed the boy writhing in pain on a hospital trolley, with bandages around his head, and his parents, both farmers, crying.

The Beijing Times newspaper quoted the parents of the boy, whose family name is Guo according to police, as saying that their son had told them he was walking along a path when he was grabbed by a woman.

She used an unspecified tool to gouge out his eyes, they said.