Syria has said that 29 people had died of cholera in what the UN has called the worst outbreak of the disease in the war-torn country for years.
Rapid assessment testing has confirmed 338 cases since the outbreak was first recorded last month, Syria's health ministry said on Monday.
It said 230 cases were in the northern Aleppo province, where 25 people were confirmed dead. The rest were spread across Syria.
The UN said this month the outbreak was believed to be linked to irrigation of crops using contaminated water and people drinking unsafe water from the Euphrates river, which bisects Syria from the north to the east.
The highly contagious disease has also spread to the country's Kurdish-held and opposition areas in north and north-western Syria, where millions have been displaced by the decade-long conflict, officials said.
Suspected cases have risen to 2,092 in the north-east of Syria, the US-based International Rescue Committee which operates in the northern region said. It said that there were fears of significant under-reporting of cases.
Western NGOs say access to safe drinking water is a huge challenge in Syria. The country has 40 per cent less drinking water than before the conflict began after widespread destruction of national water infrastructure.
Water scarcity is further compounded by climate change.
The Syrian Civil Defence, comprising rescue workers operating in opposition territory, said on Monday that medics reported the first three cholera cases in the overcrowded Kafr Lusin camps near the border with Turkey.
"This is a dangerous development for civilian lives with the start of the spread of the disease quickly under bad health conditions and especially in the camps," the Western-backed group said.
The UN has warned of high mortalities if cholera spreads in the densely populated strip. Tens of thousands of displaced Syrians live in dire conditions there, with limited supplies of safe water and sanitation.
The World Health Organisation had already begun sending urgent shipments of medical supplies and chlorine tablets for water purification, officials said.
Before the recent outbreak, the WHO said the water crisis had caused an increase in problems such as diarrhoea, malnutrition and skin conditions.
