An unknown disease killed 143 people in the Democratic Republic of the Congo's southwestern province in November, local authorities told Reuters.

Infected people had flu-like symptoms, including high fever and severe headaches, Remy Saki, deputy governor of Kwango province, and Apollinaire Yumba, provincial minister of health, said on Monday.

A medical team has been sent to the Panzi health zone to collect samples and carry out an analysis in order to identify the disease.

The situation is extremely worrying as the number of infected people continues to rise, civil society leader Cephorien Manzanza told Reuters.

"Panzi is a rural health zone, so there is a problem with the supply of medicines," Manzanza said.

Sick people die in their own homes for lack of treatment, Saki and Yumba said.

A local epidemiologist said women and children were the most seriously affected by the disease.

A WHO spokesperson said on Tuesday the UN health agency had been alerted to the presence of the disease last week, and it was working alongside Congo's public health ministry to make further investigations.