LILONGWE (Reuters) - Police in Malawi have arrested 200 suspected members of vigilante mobs that have been killing people they believe are vampires, a spokesman said on Tuesday.

Nine people have been killed since mid-September in southern Malawi where there is a widespread belief in witchcraft. The violence has prompted the United Nations and the U.S. embassy to declare some parts of the country no-go zones.

The attacks spread last week to Blantyre, Malawi’s second largest city where a 22-year-old man was stoned then burned to death and another was stoned to death.

Both were accused of bloodsucking, although medical experts deny the existence of vampirism in Malawi.

Amos Daka, head of the Medical Society of Malawi, said his group was not aware “that any one has adequate clinical evidence to support any of the many claims to date.”

President Peter Mutharika has visited parts of the country affected by the violence. This month, the United Nations pulled staff out of two areas in southern Malawi.