At least six people were killed after torrential rains slammed the Haitian capital late Monday, turning roads to rivers, collapsing fragile houses and swamping the city's squalid camps set up after last year's earthquake.

The worst rains to hit the impoverished country so far this year paralyzed the city, with three people dead in house collapses in the upscale neighborhood of Petitionville, according to Alta Jean Baptiste, Haiti's civil protection director.

Two people were killed as rushing waters soaked the downtown tent camp near the ruined presidential palace, and one person was reported killed in the town of Belladere, east of the capital, Jean Baptiste said.

Newly elected President Michel Martelly said he was en route to the city's most impoverished neighborhood Cite Soleil, which officials said was completely swamped by the storm.

"I was in the streets during the rain, and I got home, put my boots on, and I'm back in the streets to assess the situation," Martelly said in remarks broadcast on national television.

"I'm now trying to help people, and distribute some food. I hope people can find shelter," said Martelly, who was with members of his new cabinet as he handed out supplies.

The rains had meanwhile brought the entire city to a virtual standstill as waters rushed through streets and cars were jammed up in long lines, some abandoned by their owners.

Thousands of Haitians have been living rough in the capital since the disastrous 7.0 magnitude earthquake in January 2010.

Heavy rains are set to impact many here as this year's hurricane season just begins, amid fears of health officials who warn against an uptick in fatalities from a cholera outbreak that broke out in October last year.

The quake ravaged Port-au-Prince, killing more than 220,000 Haitians and leaving 1.2 million homeless in the impoverished Caribbean nation.

That toll has however been significantly downgraded in recent weeks by a not-yet released USAID-commissioned report, which contends between 46,000 and 85,000 people were killed in the quake.