Relief efforts in Haiti are now focusing on providing food and drinking water for quake victims with special emphasis on improving sanitation so as to prevent outbursts of such endemic diseases as cholera, malaria and the dengue.

The World Food Program (WFP) on Saturday started issuing food tickets which Haitians can use to trade for food portions on Sunday, when a 15-day emergency ticket-for-food relief program begins.

Up to 2.4 million people will benefit from this special program which is aimed at preventing further chaos during food distribution.

More than a dozen distribution spots will be set up in the Haitian capital to facilitate the project, a WFP spokesperson said on Saturday.

"We will be forming 16 fixed distribution sites around the city. We aim to reach 10,000 people at each site," said Marcus Pryor.

The UN body has so far provided food for around 650,000 Haitians in the 18 days after the killer earthquake hit the Caribbean island country on Jan. 12.

The Haitian authorities said that the magnitude-7.3 quake has destroyed the country's food supply system.

"Each family will be allotted 60 pounds (27 kg) of rice. Only female heads of household will be allowed into the distribution area to bring the food out," the WFP spokesperson said. "We will be loading and transporting during the night because of the dense population and traffic within Port-au-Prince."

The same procedure will be repeated on daily basis and at the end of the 15 days, the WFP will re-assess the situation to see if it is reaching those most in need.

The Haitian capital experienced chaos in the last couple of weeks when hungry crowds overwhelmed Uruguayan Air Force and Brazilian Army food distributors.

The United Nations said that such chaos occur when available food greatly undershoots the number of people arriving for it.

On Saturday, an estimated 2,000 people from a refugee camp near the presidential palace used a single portable toilet while others were forced to use a gutter running close to the camp.

Water had been recycled when it was brought in by trucks. Women in the camp used the scarce, sometimes even unclean water to wash vegetables and cook food first before recycling it as bathing water.

The United Nations institutions and other aid organizations have started digging latrines for 20,000 people, according to UNICEF coordinator for water and sanitation Silvia Gaya.

But an estimated total of 700,000 people are currently residing in refugee camps after the Jan. 12 earthquake.

More international institutions are joining the UN-led efforts to build latrines and to handle solid waste disposal.

While UNICEF and some NGOs are registering children who may have been separated from their parents or families by the magnitude-7.3 temblor, some American nationals were reportedly held by local Haitian authorities for allegedly taking some Haitian children to the Dominican Republic without proper travel documents.

An Associated Press report said that these Americans, from the state of Idaho, would appear in front of a local judge on Monday.

Advocates both in Haiti and in other countries have cautioned that with so many people still unaccounted for after the quake, adoptions, especially cross-border adoptions, should not go forward until after it can be established that the children have no relatives to take care of them in Haiti.

International relief efforts are still overwhelming Haiti's Toussaint Louverture International Airport where over 100 flights can arrive to land in a single day.