At least 97 Indian schoolchildren are being treated in hospital after getting sick from eating free school lunches, authorities told CNN.

The children, from a state-funded rural school in the Palghar district, of the western state of Maharashtra, are under medical observation after complaining of abdomen pain and nausea after eating the meal, district health officer Santosh Gaekwad said Friday.

They are hospitalised but none are in a serious condition and are improving under medical observation.

Police were unable to immediately confirm the ages of the school children but Shrikrishna Kokate, an additional police superintendent, said Thursday the oldest were students in seventh grade.

All government schools in India are mandated to provide free meals to students below the age of 13 following a decision in the country's Supreme Court in 2001.

In 2013 more than 20 children died after eating toxic lunches provided by their school in eastern India.

•Photo shows Indian schoolchildren during a lunch break.