At least 20 people have lost their lives in floods and landslides in Bangladesh as a result of torrential water coming downstream from the Himalayas, according to government disaster officials on Monday.

Deadly floods and landslides are common across South Asia during the monsoon season from June to September but experts say climate change is making them worse.

In India’s northeastern Meghalaya state, “relentless rainfall-induced floods and landslides” had caused a swath of destruction, the chief minister’s office said.

“We are saddened to inform that the death toll from the landslides and floods in the Garo Hills region has increased to 15,” it said in a statement, with the deaths recorded since Friday.

Those killed include a teacher and his son, who drowned when floods swept away their car.

In  Bangladesh -- a low-lying nation with large areas made up of deltas where the Ganges and the Brahmaputra wind towards the sea -- five people have been killed since Saturday, the disaster management ministry said.

During the monsoon season, which runs from June to September in South Asia, deadly floods and landslides are frequent, but especiallyIt further stated that at least 20,000 people had to leave their houses, although the water levels are starting to fall.

According to emergency ministry official Nazmul Abedin, "Floodwaters have started to recede... excessive rain and the water from upstream caused this flood."