The recovery of more than 200 bodies in Haiti, following severe flooding there and in neighbouring Dominican Republic, has pushed the death toll beyond 500.

The Haitian government said Wednesday that most of the bodies were found in the southern towns of Grand Gosier and Mopou where floods had caused a river to burst its banks.

Haiti's Civil Protection Director Marie Alta Jean-Baptiste said another 158 were missing in the town of Fond Verette. That's just across the border from the Dominican town of Jimani where more than 280 people have been reported dead.

Days of heavy rainstorms have been lashing the mountainous island of Hispaniola, which is shared by the two countries.

The rains have caused rivers to burst their banks, sending muddy floodwaters rushing into towns filled with flimsily-built wooden shacks.

The worst-hit areas include the poverty-filled Dominican town of Jimani, near the border with Haiti, and the districts east of the Haitian capital, Port-au-Prince.

Hampered by debris-strewn roads and persistent flooding, officials have been struggling to determine the full extent of the tragedy. Nearly bankrupt, the Haitian government has few resources to deal with natural disasters.

For that reason, Canadian and American troops are pitching in. The troops, who were sent to Haiti in the aftermath of the ouster of President Jean-Bertrand Aristide, are helping to search for survivors and with emergency work.

Six Griffon helicopters are being used to ferry personnel from Port-au-Prince to the devastated area, around three kilometres from the Dominican border.

"That would include rescue workers, non-governmental organizations as well as military personnel who are working with the multinational interim force," said Capt. David Devenney, a military spokesman.

Dominican authorities estimate more than 13,000 have been rendered homeless by the surging waters.