At least 13 people have been killed and 4.5 million affected by floods triggered by heavy rains in eastern Bangladesh, the Ministry of Disaster Management and Relief says.

Floods triggered by torrential rains have swamped swaths of low-lying Bangladesh and rescuers are scrambling to evacuate flooded communities.

The ministry said on Friday that nearly 190,000 people were taken to emergency relief shelters and 11 of the country’s 64 districts were affected by the flooding.

Feni, about 100km (60 miles) northwest of the main port city of Chittagong, was worst hit.

The South Asian nation of 170 million people, crisscrossed by hundreds of rivers, has seen frequent floods in recent decades.

It is among the countries most vulnerable to disasters and climate change, according to the Global Climate Risk Index.

Three of those who died drowned in floodwaters in the southeastern region of Cox’s Bazar, chief administrative officer of Ramu district Rasedul Islam said.

The annual monsoon rains cause widespread destruction every year, but climate change is shifting weather patterns and increasing the number of extreme weather events.

The army and the navy have been deployed, with speedboats and helicopters rescuing those stranded by the swollen rivers.