Landslides in last two days killed at least 70 people in the port city, raising such death toll during the last three decades to over 200.

Experts attribute such landslides mainly to the hill cutting, said persons working in the field.

"We warned several times that the places where landslide occurred had become vulnerable due to hill cutting. But proper measures were never taken to stop the practice," Dr Shahidul Islam, Geography professor of Chittagong University, told The Daily Star over telephone yesterday.

Dr Shahidul conducted a survey that came up with the findings that over one hundred hills have disappeared due to hill cutting during the last 30 years.

The survey report identified Khulshi, Panchlaish, Nasirabad, Pahartoli, Sholoshahar, Bayezid Bostami, Foy's Lake, Lalkhan Bazar, Oxygen intersection and Polytechnic areas as badly affected due to the widespread hill cutting.

Silimpur under Sitakunda, Jungle Pahartoli under Hathazari upazila and some other parts in the district also faced rampant hill cutting until recently, the report said.

ASM Maksud Kamal, national expert, Earthquake and Tsunami Preparedness, UNDP, said no risk of landslide is involved if the hills are cut with a slope of 20-30 degrees. But the hills in Chittagong were cut with slopes of 70-80 degrees, making those hills highly unstable.

"People also build houses on the hill top and on the slope cutting the trees and it blocks rill or gully of the hills. So the rainwater enters into the hills through cracks making big chunks of earth weak and due to the force of gravity landslide is caused," he said.

"Following the present interim government's takeover, the cutting has temporarily stopped. We have plans to file writ petitions in the High Court to stop the hill cutting permanently," advocate Anawarul Islam Touhid, who works with Bangladesh Environmental Lawyers Association, said from Chittagong.

Persons working with the issue of hill cutting in Chittagong said influential political leaders, truck owners' association, contractors, brick kiln owners, real estate developers and local goons used to conduct the hill cutting business through managing some government officials concerned.

In many cases, they worked as a syndicate and as several influential leaders of big political parties operated the hill cutting business from behind the scene, no effective measure could be taken on the issue, said an environment activist working in Chittagong.

The Ministry of Environment and Forest and the Chittagong Development Authority (CDA), in view of widespread destruction of hills in the district through hill cutting, issued a circular in 2005 prohibiting hill cutting in the district.

The CDA and Department of Environment filed around 100 cases in connection with hill cutting but no further steps were taken.