At least 20 people are dead after a horror fire ripped through an amusement park packed with children for the summer holidays in India.

The massive blaze erupted in a two-storey structure in the fun park in Rajkot city, Gujarat state.

Footage shows thick black smoke billowing from flames that raged for about an hour as firefighters battled to contain the inferno.

About 300 people were reportedly in the bowling, go-karting and trampolining section of TRP Games Zone at the time of the deadly tragedy.

A rescue operation underway on Sunday morning (AEDT) had so far recovered 20 bodies.

Firefighters trying to extinguish the blaze in the two-storey structure. Photo: Getty

Fire officials reportedly believe the fire was caused by a short-circuit.

Police said they would be filing a negligence case against the park’s owner Yuvraj Singh Solanki.

“We will be registering an offence for negligence and the deaths which have occurred,” said Police Commissioner Raju Bhargava.

“Further investigation will take place once we complete the rescue operation.”

The cause of the fire is under investigation.

Prime Minister Narendra Modi wrote on X that he was “extremely distressed by the fire”.

“My thoughts are with all those who have lost their loved ones. Prayers for the injured.”

“The fire tragedy in Rajkot has saddened us all.

“In my telephone conversation with him a short while ago, Gujarat CM Bhupendrabhai Patel Ji told me about the efforts underway to ensure all possible assistance is provided to those who have been affected.

Tweet from @narendramodi

-with AAP