"If a tremor of an intensity of 7 hits the capital, at least a quarter of its houses will collapse. The percentage will shoot up to 42 percent if the intensity is 8," says Prof Jamilur Reza Choudhury, vice chancellor of Brac University and an expert in structural engineering.

He says, in case of a large earthquake "the number of deaths will be at least several thousands, with wounded in lakhs".

Choudhury puts Dhaka, which houses about 13 million people and an unbelievable number of poorly constructed, dilapidated buildings, at the top of an earthquake disaster risk index of the world's 20 most vulnerable cities he had prepared back in 1998.

Experts say Bangladesh is seismically active. The occurrences of earthquakes of an average magnitude of 5 in the Richter scale are quite frequent, especially in the eastern region.

According to them, micro-seismic data indicate that at least four earthquake source-points exist in and around the capital. They identify the western part of the city from Mirpur-Kalyanpur to Pagla along the Buriganga River and the eastern part from Uttar Khan-Badda to Demra along the Balu River as the two most high-risk zones.

The rate of strain accumulation is also high in the city's subsoil, which in case of a release may cause a tremor of an intensity of 6.8 in the Richter scale, experts say. The shallow subsurface of the city is also characterised by a number of faults.

Luckily, Dhaka has not experienced any moderate to large earthquakes in the recent past. Yet the earthquake on December 19, 2001 of a magnitude of 4.5 and a focal depth of 10km located very close to the city is a certain indication of its vulnerability.

For many years now, experts have been warning of a catastrophic tremor causing heavy casualties and destruction of property in the densely populated capital and other metropolitan areas, as the developers do not follow the Building Code meticulously.

Choudhury says the authorities should be strict on observance of the code.

The experts say we should not delay any more to act to minimise the losses of lives and property in earthquake. They also want to see earthquake-monitoring networks at work in the country.