Turkey's prime minister says he has ordered architectural changes in an eastern region where 51 people were killed in an earthquake.
Prime Minister Recep Tayyip Erdogan blamed the high level of casualties on mud-brick buildings used in the area.
Survivors have been huddling around fires in near-freezing temperatures, as rescue teams hand out food.
The 6.0-magnitude quake struck before dawn on Monday, toppling buildings in five villages.
The destruction was said to be worst in the Kurdish village of Okcular, where at least 15 people were killed.
'Lessons to learn'
"Unfortunately, houses made of sun-dried brick constitute the architecture in the region," said Mr Erdogan.
"We have given necessary directives to the provincial authorities to change the architectural structure."
Mr Erdogan also said he had ordered the start of a reconstruction project in the area.
He was speaking amid calls for Turkey to learn lessons from the quake, which commentators said would not have caused such a high toll in other earthquake-prone countries such as Japan.
"An earthquake with this magnitude should not usually cause any deaths, but mud-brick houses and other buildings that are not resistant to earthquakes can cause so much death and destruction," earthquake expert Ahmet Mete Isikara told Turkey's Hurryiet Daily News and Economic Review.
A commentary in the country's Vatan newspaper said: "Those who rule the country... should prove to us through their actions that they have learnt their lessons from what happened."
Residents of the affected villages have been warned not to return to damaged homes as the area was shaken by dozens of aftershocks, the strongest of which measured 5.5.
The government disaster management centre and Turkish Red Crescent have set up tents to help survivors cope with the harsh winter weather, and are also distributing food and blankets.
Turkey, which is crossed by the Northern and Eastern Anatolian fault lines, suffers from frequent earthquakes.
Many of them are minor, though a 7.4-magnitude tremor which hit the western city of Izmit in August 1999 killed more than 17,000 people.