Police were last night investigating the mysterious death of a 13-day-old baby.

The infant died yesterday morning after being taken to hospital with breathing difficulties - two days after she was thrown to the ground when a car struck her pushchair.

However, detectives investigating the death said last night that they were not linking the tragedy with the accident.

The baby fell from her pushchair after it was struck by a car, which had veered out of control, through a fence and into a garden in Queensway, Houghton-le-Spring, Wearside.

After the accident, the baby was taken to Sunderland Royal Hospital for observation. She was released the same day.

Paramedics were called to her parents' house in Kirkstone Close, Houghton-le-Spring, at 7am yesterday after she developed breathing difficulties.

The baby was taken to Sunderland Royal Hospital by ambulance, but died shortly after arrival.

A spokeswoman for Northumbria Police said: "This is the same baby which was involved in the road traffic collision in Queensway on Saturday.

"The baby was taken to Sunderland Royal Hospital for further examination and observation and later released with no apparent injuries.

"Police are investigating the death of this child. It is not being treated as suspicious at this time.

"There is no link at this stage between the crash and the death of the baby.

"Police are continuing to investigate."

The accident happened at 12.50pm on Saturday while the baby was being looked after by a family friend.

The infant was in her pushchair in the garden when a Fiat Punto crashed through the fence and knocked it over.

The Punto, which was being driven by a young woman, had clipped a Vauxhall Astra just before the accident.

Norman Turton, who lives opposite the babysitter in Queensway, was driving the Astra.

"It was unbelievable," he said. "I was in shock and people were running around screaming and crying about what had just happened.

"Everyone's concern was for the baby and someone called an ambulance.

"It seemed all right and was taken to hospital."

Painter and decorator Mr Turton, 63, learned that the baby had died from his partner, Maureen Box, 53.

Miss Box said: "I was on the bus when I heard from a friend and I just froze.

"We live in a very tight- knit community and everyone is very upset and stunned."

Mr Turton said news of the baby's death had rocked the estate.

He added: "I cannot understand it because they came back and said the baby's fine and back with its mother and father.

"What has happened is heart breaking. The whole street is in shock.

"I know the parents and they are a lovely family. I want them to know how very sorry I am for what they going through."

The family were too upset to talk about the tragedy yesterday.

Sunderland Royal Hospital declined to comment.