Suspected cases are being investigated in three new departments, health officials report.

They said nearly 300 people were now known to have died in the cholera outbreak.

The UN is investigating allegations that excrement from Nepalese peacekeepers caused the epidemic.

The Nepalese camp had become the object of local suspicion partly because cholera is very rare in Haiti but endemic in Nepal.

Tests taken from the peacekeepers' camp and adjacent waters last week were found to be negative, said a spokesperson for UN Secretary-General Ban Ki-moon.

Results from additional tests taken at the base this week were expected on Friday, added the spokesman, Martin Nesirky.

Sarah Jacobs from the aid organisation Save the Children told the BBC that 174 new cases of cholera were being investigated in the area around Arcahaie, a village in the northern Port-au-Prince district and about an hour's drive from the capital.