New York (PTI): The United Nations has sought stricter codes to ensure that buildings are able to withstand earthquake shocks considering the large number of casualties caused due to their collapses.

"We know how to make buildings more resistant to earthquakes, but this knowledge is still not yet well disseminated among decision-makers who enforce building codes for houses, schools and hospitals," said Salvano Briceqo, Director of UN International Strategy for Disaster Reduction (ISDR).

When earthquakes strike, collapsed buildings claim the largest number of lives, as made evident by tremors in Pakistan in 2005, Iran in 2003 and most recently in China earlier this week, he said.

Hundreds of thousands of buildings, including many schools, caved in when Monday's deadly earthquake measuring about 7.9 on the Richter scale struck Sichuan province in southwest China.

"Schools, hospitals and other critical infrastructure need to be systematically upgraded and retrofitted in earthquake-prone areas if we want to save lives," Briceqo said. "Vulnerability to earthquakes is still a main cause of death during disasters."

The Director is currently in Islamabad for the three-day International Conference on School Safety which aims to identify actions to enhance safety in schools in the region.

Participants visited Balakot in Pakistan's North West Frontier Province, the site of the 2005 earthquake.

ISDR, the UN Educational, Scientific and Cultural Organisation (UNESCO) and the UN Children's Fund (UNICEF) joined forces for a global 2006-2007 campaign called "Disaster Risk Reduction Begins at School" in a bid to promote school safety, while the WHO and the World Bank have partnered in a 2008-2009 campaign to encourage safety in hospitals and health facilities.

"There are still too many poorly designed and constructed buildings in earthquake-prone areas, and too many people dying because of it," Briceqo said.