Haiti has been hit by more than 50 aftershocks since a 7.0-magnitude quake hit the country on January 12, and each one brings new terror to the devastated people.

Fighting for shelter

With an estimated one million people left homeless, competition for tents has boiled into arguments and fights in some parts of the city.

special report
Special Report: Haiti earthquake

Rene Preval, Haiti's president, urged the world to urgently airlift 200,000 more tents and 36 million ready-to-eat packs before the rainy season starts in May.

Aid organisations fear disease could spread rapidly if
thousands of people are still living in the tent cities when the rains come.

As well as a scarcity of shelter, delays in getting food aid to the starving survivors of the quake persist.

UN troops fired tear gas at desperate Haitians crowding a food handout outside the wrecked presidential palace on Tuesday.

"They're not violent, just desperate. They just want to eat," Fernando Soares, a Brazilian Army Colonel, said.

"The problem is, there is not enough food for everyone."

The international relief effort has struggled to get enough aid into the capital and out towards flattened towns near the quake's epicenter, stoking security fears.

The US has dispatched more than 15,000 military personnel to Haiti. About 4,700 are deployed on the ground with the rest on ships off the coast.

The US military said it could scale back its involvement within three to six months as other international organisations assume larger roles providing security and disaster relief.

It plans to help build a 5,000-bed hospital to provide longer-term care to quake victims.