Damage to water supplies is being blamed
The World Health Organization (WHO) says it expects a cholera epidemic in southern Iraq because of problems with poor sanitation.
WHO disease specialist Denis Coulombier estimated that there were 10 times the number of cholera cases than the 17 registered in Basra since Tuesday.
Another WHO official said the organisation "feared hundreds of cases".
We expect a cholera epidemic in southern Iraq and we fear hundreds of cases
Although cholera is always present in Basra, particularly in the hot months, the number of cases reported in a 24-hour period is causing alarm, says the BBC's Jane Peel in Basra.
The WHO is meeting British troops who control the region, the Red Cross and local health officials to step up efforts to improve sanitation in the area in a bid to avert the epidemic.
Tests on the 17 cases are being carried out in Kuwait and the results will be known on Thursday, WHO spokeswoman Fadila Shaib said.
In other developments:
- US-led forces say they have detained a senior member of Saddam Hussein's Baath Party - Ghazi Hamud al-Adib
- US officials are preparing to examine a tape containing a message allegedly recorded by Saddam Hussein in the last few days, released by an Australian newspaper
- Former US State Department official Paul Bremer is appointed as the top civil administrator in Iraq.
Doctors in Basra's main hospital have reported a significant rise in the number of cases of diarrhoea, gastro-enteritis and dehydration - particularly among young children.
Caused by drinking or bathing in contaminated water, or eating food washed in this water
Incubation period of 2-5
Attacks intestine, causing diarrhoea and dehydration
Can be fatal if untreated
"Since the beginning of the war, the WHO has said that the potential for a large outbreak of diarrhoea diseases does exist with a shortage of clean water in the south and the fact that people who do not have the choice use contaminated water from the river for their daily consumption," said Fadila Shaib.
The current outbreak is being blamed on disruption and damage to the water supplies caused by the recent conflict in Iraq.
City residents went for several weeks
without running water, and many resorted to collecting drinking water from the Shatt al-Arab river or extracting water from working pipelines.
Many water pipes were broken during the looting that took place after the war.
Repairing the damage has been slow because of the lack of security on the streets, our correspondent says.
Hospital workers say sewage is not being disposed of, and rubbish is only being collected intermittently, which adds to the problem.
People in the region who do not have access to potable water were urged to boil water before drinking it.