Blantyre - Vigilantes in Malawi have killed six people suspected of trying to obtain and drink human blood as part of magic rituals since mid-September, police told AFP on Tuesday.
Malawi, where witchcraft is widely believed and education standards are low, is regularly dogged by rumours of "vampire" activity.
The six people were killed in three separate incidents in the area surrounding Mulanje Mountain in the country's south.
The most recent attack came on Sunday when an angry mob beat two people to death because they "suspected the two (victims) of being blood suckers", said police spokesperson James Kadadzera.
The victims were travelling to pray close to the mountain when they were intercepted by a violent crowd on their way through a village.
In another incident, Kadadzera said a local chief was killed by a group accusing him of colluding with men suspected of consuming human blood.
"There is no evidence about the blood suckers... we blame communities for taking the law into their hands," he said, adding that local people targeted the victims because they were believed to be seeking blood for spiritual rituals.
"There is no evidence of blood sucking and nobody has come to police to complain."
Police have deployed more than 100 riot officers to the region in response to the killings.
The United States embassy in Malawi has temporarily withdrawn its team of Peace Corps volunteers from the four districts bordering Mulanje and advised its citizens not to visit the area.
In a statement, the embassy blamed "ongoing acts of vigilante justice stemming from rumours of persons attempting to siphon blood from local residents for ritualistic use."
In the 1970s, the government of former dictator Hastings Kamuzu Banda was accused of killing a dozen residents in a suburb of southern city Blantyre in order to send their blood to apartheid-era South Africa.
Although the culprit was eventually caught and jailed for life, the murders still haunt Malawi.
The issue of vampires remains a sensitive one for officials in Malawi.
In 2003, police arrested a radio journalist for interviewing a man who claimed his village was visited by blood-sucking vampires. He was later released.
The government has previously been forced to deny that it collaborates with international aid organisations to take blood from impoverished villagers in exchange for food supplies.