A two-year-old girl was found in the street with “life-threatening injuries” after reports she fell from a window, police said.
The girl was found in Bedford Street, Portsmouth, on Thursday evening.
She was airlifted to hospital, where her condition is described as serious but stable.
A man, 29, and a woman, 26, were arrested on suspicion of neglect of a child to cause unnecessary suffering.
They were also arrested on suspicion of possession of a weapon for discharge of a noxious liquid or gas or electrical incapacitation device and possession of a Class B drug. They remain in custody.