A blast in an Indian pharmaceutical factory has killed at least 17 people with chemicals burning the skin off several of the 34 injured, police said on Thursday.

The Hindu newspaper reported that the force of the blast had been so strong that it left severed body parts scattered around the site.

The fire broke out on Wednesday afternoon at a pharmaceutical unit in Andhra Pradesh’s Anakapalli district.

District police superintendent M Deepika said ‘rescue operations are over’ and all were accounted for, with a final toll of ‘17 dead and 34 injured’.

She added that investigators believe the blast was caused by a ‘gas leak which eventually hit an electrical panel’.

Local police official M Buchaiah told the Indian Express daily that those caught in the blast suffered horrific chemical burns.

‘It was horrible, heartbreaking,’ he told the paper, describing the pain people suffered as those who survived were carried to ambulances.

‘They were screaming before they lost consciousness’.

Prime minister Narendra Modi on Thursday said that he was ‘pained by the loss of lives’, in a post on social media, announcing compensation of $2,380 to the families of those killed.