The struggling aid effort in Haiti was hit by another setback on Monday as the UN halted deliveries to some 10 000 quake survivors after discovering that fake coupons were in operation.

An agitated crowd of around 100 people continued to wait well into the afternoon at the drop-off site close to the town hall in the Port-au-Prince suburb of Petionville as others clamoured to get tickets valid for Tuesday.

"We need food!" one old lady shouted at a guard charged with manning the steel bars blocking the entrance to the town hall offices.

Others simply pointed to their mouths and stomachs.

UN World Food Programme spokesperson David Orr said the suspension would affect around 10 000 survivors of the massive 12 January earthquake that killed over 212 000 people and left an estimated one million people homeless.

The UN agency has set up 16 food distribution points across the city, handing out 25-kilogram sacks of rice designed to feed a family for two weeks.

Orr said World Food Programme partners hoped to restart the distributions at the affected site on Tuesday.

'I am trusting God'

Meanwhile, Laura Silsby, the leader of a group of 10 American missionaries arrested at the Dominican border for trying to smuggle out a busload of children appeared in court to answer kidnapping charges.

"I am trusting God to reveal all truths and that we will be released and exonerated of charges, and we are just waiting for the Haitian legal process to complete," Silsby said.

"It went very well," she told reporters as she left the hearing and was taken back to the police station where she and her nine colleagues from the Idaho-based New Life Children's Refuge are being held.

The other nine were expected to be heard on Tuesday.

"We're doing very well. God is good. He's sustaining us. We've been given great care," she said.

The defendants, who acted without authorisation from the Haitian government, claim they meant no harm and simply wanted to give the children a better life in an orphanage they planned to set up in the Dominican Republican.

But soon after their arrest on 29 January it emerged that several of the 33 children were not orphans, although some of their parents have admitted they agreed to give away their kids.

"The children have parents," acknowledged lawyer Aviol Fleurant, who is representing the Americans after their previous attorney quit the case over accusations he was trying to bribe the judge.

"They were there in the name of humanity, in the name of the human heart to help Haitians cross the border because everything was dysfunctional in Haiti at the time," Fleurant said.

A final decision from the judge is expected within three months after the proceedings are completed and the Americans face lengthy prison terms if convicted of child trafficking and criminal conspiracy.

The case has been criticised as a distraction from the stumbling international aid effort to bring Haiti, already the poorest nation in the Americas before the 12 January tremor, back on its feet.

Queuing for precious passports

Haitian President Rene Preval was expected in Quito on Tuesday for a donor conference organised by the Union of South American Nations (UNASUR).

The situation in the Caribbean nation, almost one month after the disaster, is still dire as disease breaks out in squalid makeshift camps and the massive aid effort struggles to house people before the arrival of seasonal rains.

At the central immigration bureau, hundreds of Haitians queued in line for a precious passport to leave. Others simply massed in front of the entrance.

An official directing the crowd with a bullhorn said only renewals would be handled due to overwhelming demand and that those wanting a passport for the first time would have to come back next week.

Crowds have swelled ever since the bureau reopened after the quake, said the official, who requested anonymity because he was not authorised to speak on the matter.

Massive lines of visa seekers have also appeared before the US embassy.

A man waiting in front of the immigration office said he had been coming every day for about a week, hoping to join his parents in France. He said the destruction has left him seeking a better life for his family.

"Everybody's looking for a way to leave," said Jourdain Jean Nickson (30).