At least two states, Tripura in the northeast and West Bengal in the east, ordered schools to shut this week, as temperatures rose more than 5°C above normal, state governments said.

Kolkata, the capital of West Bengal, recorded temperatures of 40°C on April 13 and 41°C on April 14, more than 5°C above normal for the time of year, said G K Das, an official at the state weather office, told Reuters.

India is likely to experience heatwaves between March and May, the national weather office said in February.

The average maximum temperature in February across India was 29.54°C the highest since 1901 when the IMD started keeping weather records.

Scientists have linked the early onset of an intense summer to climate change, and say more than a billion people in India and neighbouring Pakistan are in some way vulnerable to the extreme heat.