At least four people were killed, and five others injured in a boiler blast in India's eastern state of Bihar on Saturday, local media reported.

The incident took place while the workers were preparing a mid-day meal for several schools in an NGO's kitchen in Sugauli area of Motihari district, said local media. 

The injured have been shifted to Sugauli Primary Health Centre hospital for treatment.

Relief and rescue work is still ongoing at the site of the blast, according to local police.