More than five lakh people in Sylhet remain marooned as flash floods hit five upazilas. The floods were triggered by heavy rains in the border areas of the district and India's Meghalaya.

The district administration opened 470 shelters and started distributing relief among the flood-hit people.

With the Surma, Kushiyara, and Sarigowain flowing above the danger level since Wednesday, most areas of Gowainghat, Companiganj, Jaintiapur, Kanaighat, and Zakiganj upazilas have gone under water.

Lutfur Rahman, an elderly man of Rangpani area in Jaintiapur upazila, took shelter on a truck on Sylhet-Tamabil highwaywith his family.

"Water began entering my village yesterday [Wednesday] evening. Around 3:00am, my house was waist-deep in flood water. We rushed to the highway and took shelter on the parked truck," he said.

The Sylhet-Tamabil highway and many other roads of the five upazilas have been flooded, disrupting road communications.

Sajidur Rahman Sajon of Ferighat area in Jaintiapur in several Facebook posts on Wednesday night requested that he and his family members be rescued from their home.

"All praise to the almighty. We were rescued safely early this [yesterday] morning. We were afraid as water level was increasing faster than ever before," he told The Daily Star.

According to the Flood Forecasting and Warning Centre of Bangladesh Water Development Board, the Surma river was flowing 138cm above the danger level at Sylhet's Kanaighat point at 6:00pm yesterday, the Kushiyara 213cm above the danger mark at Zakiganj's Amolshid point, and the Sarigowain 33cm above the danger level at Gowainghat point.

The Surma at Sylhet point may cross the danger level in the next 24 hours and the overall flood situation in Sylhet may deteriorate. The situation may improve in the following 24 to 48 hours, the Met office said.