This is the heartbreaking moment a newborn baby boy was found inside a plastic bag abandoned on a bridge in Indonesia.

Dian Dinarti, who lives in the area, saw the red plastic bag on the pavement while travelling to her workplace in West Kalimantan province on November 4.

At first, she thought that the movement coming from inside the plastic was puppies so she approached to check.

However, the woman was shocked after seeing a newborn baby boy inside with its umbilical cord still attached.

Dian said: "The poor baby was not even crying when I found it. I just saw the plastic move so I approached to see what was inside. I'm so glad I did, because the baby was still alive.''

The passer-by called for help among her neighbours and motorists who stopped by and covered the baby with a blanket to warm it.

The rider asked the woman to ride pillion while carrying the baby before rushing to the hospital. They left the baby to the doctors before reporting the incident to the police station.

Ketapang Police Detective and Criminal Unit Head Adjunct Commissioner Primas said they are now interviewing witnesses to try and find the parents of the baby.

He said: "We have started investigations and urge everyone who lives in the area who may have seen the person who did this to come and give a statement."

The baby is now in stable condition and is being cared for at the Bunda Permata Hospital.