Residents of the areas said small locally made dredgers -- known as volgates -- are extracting tonnes of sand from the riverbed day and night. They might face a similar devastation as at nearby Basila recently, they apprehend.

"Hundreds of volgates are extracting sand from the riverbed and loading it in large barges for sale to the construction sector of the capital," said Golam Murtaza of Kamrangirchar.

Locals at Kholamora also made similar allegations.

The practice continues often with the authorisation by the Power, Energy and Mineral Resources Ministry and Bangladesh Inland Water Transport Authority (BIWTA), they said.

"Indiscriminate extraction of sand from riverbed may not only change the channel of a river but also cause turbulence in water flow and erosion of its banks," a dredging expert of the BIWTA said.

In the wake of the Basila erosion in which the Buriganga devoured 27 houses between August 13 and 28, a cabinet committee discussed the matter and decided that the mineral resources ministry would no longer authorise anyone to extract sand from the riverbed.

A law enacted in 1992 however allows them to permit extraction of sand from riverbed.

A BIWTA official said the cabinet committee decision on August 21 is yet to be announced officially.

BIWTA dredging experts pointed out that authorisation by the mineral resources ministry does not impose any restriction on how much sand could be extracted and how it should be extracted. The authorisation is 'easy to obtain' and it does not have any scientific basis. The ministry also lacks monitoring cell to oversee the extraction.

"The only thing the authorisation mentions is the area where sand can be extracted and thousands of people have obtained it," said one expert requesting anonymity.

The authorities have now asked the BIWTA to issue authorisation for extraction of sand from the riverbed on the 17-kilometre stretch of the Buriganga from Kholamora to Fatullah.

But along the river from Basila to Kholamora, dozens of volgates were found extracting sand during the last one week. Asked about

authorisation, workers of a volgate named Allar Dan said they did not have any.

The operator of the volgate said no-one has any authorisation to extract sand from the riverbed.

According to Mashud, a sand trader at Amin Bazar, they buy at least 10 barges of sand a day. Sand trade is a big business in the booming construction sector and sand is also being used to fill up miles of low-lying land around the capital, he added.

"What you see here is nothing compared to how much is being dumped on the low-lying land," Mashud said pointing his finger at the huge piles of sand on the bank of the Turag river.