But the prayers come amid growing complaints from some Haitians about the lack of food, sanitation supplies, and shelter provided by the government and aid agencies.

Al Jazeera's Jonah Hull, reporting from the Haitian capital, said signs had been emerging of real frustration at the way the government has handled the crisis.

He said small protests had been growing in frequency in recent days, and sources had told Al Jazeera that preparations were under way for a new wave of more organised demonstrations in the week ahead.

Some protests have been organised by the party once headed by Haiti's exiled former president, Jean Bertrand-Aristide.

Need for shelter

"In chaos, as is so often the case, there's plenty of space for political opportunism," our correspondent said.

As a result, he said, it may not belong before the crowds that joined Sunday's prayer services turn into crowds of anger and discontent.

With the rainy season just a few weeks away, aid agencies have said there is an urgent need to step up work on providing shelter for the more than a million Haitians displaced by the earthquake.

Relief agencies are distributing plastic sheets in the run up to the rainy season [AFP]
Last week the United Nation's humanitarian chief John Holmes said the emergency medical care phase of dealing with earthquake trauma patients was "mostly over", with the priorities now on providing shelter and sanitation.

"It is urgent to get everybody with some kind of reasonably waterproof covering over their heads," Holmes told reporters after a tour of earthquake recovery sites.

He said only 30 to 35 per cent of the need for waterproof shelter has been met.

Most of the survivors made homeless by the quake are living in the streets in makeshift encampments with shelters fashioned from tarpaulins, sheets of corrugated zinc, tents and bedsheets lashed together with rope and twine.

Most of the estimated 500 camps have no water or toilets and Holmes said providing latrines was proving a major challenge.

"We need to construct something like 25,000 latrines of one sort or another, whether they be dug latrines, trench latrines or portable latrines," he said.

"We're probably not more than 5 or 10 percent of the way there."