Women and bereaved children in quake-ravaged Haiti could fall prey to human traffickers and thousands of prisoners that have escaped from collapsed prisons, officials warned on Thursday.

Some criminals took advantage of blackouts in Port-au-Prince, harassing and raping women in makeshift camps when night fell, national police chief Mario Andresol told reporters.

Women's organizations have reported several such cases to the United Nations mission in Haiti, urging swift measures to boost security for the most vulnerable survivors after the Jan. 12 temblor, said Andresol.

Life for Haitian children was already miserable before the quake as poverty forced some parents to drop their kids temporarily in orphanages.

Many children are seen roaming the rubble-strewn streets on their own after the 7.3-magnitude earthquake. A man was caught trying to steal a baby from a tent at an improvised camp.

Child trafficking was also a chronic problem in pre-quake Haiti. Many children were taken out of the country, with some feared to have been sold to illegal traders of human organs.

Children's groups and the Red Cross have begun registering parentless children and sending some to orphanages for temporary shelter, said Bo Viktor Nylund, a senior adviser for child protection with United Nations Children's Fund (UNICEF).

UNICEF is focusing on reuniting Haitian children with family members as a first option, and will spend several months actively seeking each child's parents before considering their adoption, said UNICEF press official Roshan Khadivi on Wednesday.

"We are taking photos and filling in forms to get the children's full details on file," Khadivi told Xinhua at a tent camp near the Toussaint L'Ouverture Airport in Port-au-Prince.

"Experience has shown us that there is at least one family member left usually," she said. "UNICEF does not believe in institutionalization in orphanages. Children need to be connected with their communities."

In efforts to boost security in the Haitian capital, Chinese peacekeeping riot police and U.S. troops Thursday carried out a joint patrol in the Careffour area in the western suburb of Port-au-Prince.

With a population of 300,000, Careffour had long been dominated by armed gangsters. A tactics team of 10 Chinese riot police and two squads from the U.S. 82nd Airborne Division patrolled the area.

The forces kept guard when the Haitian special police were searching for and questioning suspects. A man with tattoos on his right arm was arrested in the operation.

The situation in Port-au-Prince has improved as aid workers and peacekeeping forces have removed bodies from the streets and are trying their best to feed the hundreds of thousands of hungry people.

However, food and drinkable water are dramatically inadequate and stronger men were seen grabbing rice bags and other food handouts from women and children.

The ongoing World Economic Forum on Thursday gave special attention to Haiti, with former U.S. President Bill Clinton calling on business leaders to provide urgent aid to help rebuild the country.

"There are serious unmet food and water needs. Part of it is the distribution system does not exist," Clinton said at a special session on the long-term rebuilding of Haiti.