Charles Haviland BBC News, Colombo

At least four people have died in the vigilante violence and related confrontations.

The villagers appear to think the strangers have mysterious supernatural powers – “bionic” ones, according to a government minister.

Parts of Sri Lanka are gripped by a bizarre outbreak of panic, rage and mob violence.

Unfamiliar people

Many villagers seem convinced that unfamiliar people are guilty of local crimes, including the actual or rumoured molestation or killing of women.

Some say criminals are mutilating women for use in black magic. They’re blaming it either on civilians or security force members spotted locally.

In some cases the blame is linked to a traditional belief in what are known as “grease devils” – men thought to commit crimes while dressed only in underwear and smeared in grease to avoid being grabbed.

Four people have died, including two villagers hacked to death as suspected criminals and a man shot by security forces in the village of Pottuvil.

The Sri Lankan Justice Minister, Rauff Hakeem, who’s visiting Pottuvil, told the BBC the army shot the man amid confrontations between local people and soldiers.

Mr Hakeem was critical of the security forces but admitted he could not fathom exactly what was happening.

"Bionic powers"

He said some people believed there were criminals at large with “bionic powers”, or shoes with which they could leap huge distances.

Such rumours were spreading like wildfire and a number of innocent people had been beaten up, he added.

On Saturday things were calm after a night-time curfew and several arrests, he said.

All police leave in eastern Sri Lanka has been cancelled. Top officials say anyone taking the law into their own hands will be punished.