A condition that has killed at least 50 people in northwest Democratic Republic of Congo this month is suspected to be malaria or food poisoning, local health officials said on Thursday.

At least 943 people have also fallen sick and 52 died in Equateur province, with symptoms ranging from fever and fatigue to vomiting and weight loss, Dieudonne Mwamba, director general of the National Institute of Public Health, said.

The World Health Organization said in a statement it had identified 1,096 cases and 60 deaths fitting the definition of the illness.

"For now, our diagnosis is malaria, and we also suspect food poisoning," Mwamba told Reuters.

"It's not an unknown and mysterious disease. It's a phenomenon involving children who consumed bushmeat."

The WHO said in a bulletin on February 16 it has received reports indicating that children had consumed a bat carcass before the onset of symptoms.

A dozen samples tested negative for viral hemorrhagic fever, while 78% of the samples tested positive for malaria, Mwamba said.

"There are five villages that are affected ... The diagnostic is more pointing toward malaria," Ngashi Ngongo from the Africa Centres for Disease Control and Prevention (Africa CDC) said in a press briefing via video link.

The World Health Organization said it was stepping up surveillance and will work with local health authorities to conduct further investigations.

An outbreak of disease in December, initially of unknown cause, was ultimately identified as malaria.