Thirty-one people, mostly Burundian refugees, have lost their lives to cholera outbreak in Tanzania since last week, the UN says.

The deaths, “two locals and 29 refugees”, were reported in the port town of Kigoma on Lake Tanganyika, in the nearby villages of Kagunga and Nyarugusu, and among the people on ferries en route from Kagunga to Kigoma, the Office of the UN High Commissioner for Refugees said on Friday.

“The epidemic is still worsening. To date some 3,000 cases have been reported, and numbers are increasing at 300-400 new cases per day, particularly in Kagunga and nearby areas,” said Arian Edwards, the agency's spokesperson, speaking to journalists in Geneva.

“At this rate, further cases can be expected over the next days, until the situation can be brought under control.”

Preventive water and sanitation measures are essential, and the first two days of treatment are especially important, to rehydrate people, Edwards further noted.

“Affected refugees are being treated at newly established Cholera Treatment Centers run by International Rescue Committee in Kagunga and Kigoma and by the Tanzanian Red Cross in Nyaragusu refugee camp.”

The tiny fishing village of Kagunga, receiving between 500 and 2,000 Burundian refugees on a daily basis, suffers from a “dire situation” and the UN agency’s priority is to get the refugees out of the village.

Cholera, a highly contagious disease, is transmitted through contaminated drinking water and food and consumption of water from the Lake Tanganyika itself is believed to be the cause of the disease.

According to the UN refugee agency, over 64,000 Burundian refugees, fleeing from political unrest back home, have entered Tanzania since the beginning of May.

Pierre Nkurunziza, a former rebel leader from the majority Hutu tribe, has been Burundi’s president for two legal five-year terms. His intention to seek a third term is viewed by the opponents as a clear violation of the constitution.

The incumbent president, however, has rejected claims that he is violating the constitution by seeking to remain in power, arguing that he can still run for president as his rise to power after the civil war did not come through direct votes.

The country has been witnessing clashes since President Nkurunziza announced his plans to run for a third term in late April and scores of people have been killed and dozens of others injured since then.