At least 35 people including eight children were killed after they were struck by lightning in the adjoining eastern Indian states of Bihar and Jharkhand, officials said.

Around 18 people were killed late on Sunday by bolts of lightning across Bihar, including six children, State Disaster Management Minister Devesh Chand Thakur said.

"The children were playing in the pre-monsoon showers when lightning struck them," Thakur said from the state capital Patna.

Mr Thakur also told local media most of the victims were either farmers or the homeless who were outdoors.

Twelve others who were injured were taken to hospital, he said.

In neighbouring Jharkhand, 17 people including two children were killed by lightning strikes, also late on Sunday night, a disaster management spokesman said in the capital Ranchi.

Earlier this month nine people from villages in the Vadodara region died on a single day after a series of lightning strikes.