Estimates of the number of people who may have died in the earthquake that devastated Haiti yesterday continue to climb.

Numbers up to 100,000 have been quoted with eyewitnesses reporting many people still trapped under collapsed buildings. The United Nations estimates that around a third of Haiti’s nine million people may be affected in some way by the quake.

“Casualties can not yet be estimated but they are certain to be heavy,” said UN secretary-general Ban Ki-moon yesterday.

Appeals for more help have been issued by the UN, which says there is an urgent need for food, water, search-and-rescue teams and medical help.

Foreign rescue teams are now arriving in Haiti, and the US government is considering sending a large military force to assist in rescue and rebuilding.

The Wall Street Journal reports that in many areas rescue efforts from the government have been “nonexistent” with foreign assistance also slow to materialise:

“Who is in charge?”—Ki e ski responsab?—was a common question on the streets.

Many victims are being treated in the open or in tents amid fears about the stability of structures left standing.

“The situation is chaotic. I visited five medical centres, including a major hospital, and most of them were not functioning,” says Stefano Zannini of charity Medecins sans Frontieres. “Some parts of the city are without electricity and people have gathered outside, lighting fires in the street and trying to help and comfort each other.”

BRIEFING: The Haiti earthquake in depth