Fierce tropical storms wreaked havoc across Bangladesh on Thursday, killing more than 30 people, with police attributing many of the deaths to lightning strikes.

The death toll from the 10 worst-hit districts stood at 33, police told AFP, with reports of an unconfirmed number of casualties in more remote regions.

The northwest of the country was the worst hit, with at least 19 people killed in Pabna, Rajshahi, Sirajganj and Brahmanbaria districts as a huge electrical storm swept through the area at sunset.

"They were farmers. They were struck by lightning as they were returning home after day's work," Pabna police inspector Ahsanul Haq told AFP, referring to the six people who died in that district.

In Rajshahi, five farmers were killed as they were working in rice fields, police inspector Shariful Alam told AFP.

Four people died in Sirajganj district and a further four in Brahmanbaria, local police officials said.

In Dhaka, three students in their early 20s were hit by lightning as they were playing football in the rain, local police station chief Kawser Ahmed said.

"They were rushed to a hospital where two died," he told AFP.

A further 12 people died in the strong storms in other parts of the country.

Private station Jamuna TV put the nationwide death toll at 42.

Strong tropical storms regularly hit Bangladesh during the pre-monsoon and then monsoon season, which spans from June to September.