Witnesses say the lynch mob attacks were frenzied and indiscriminate. Even children are alleged to have been targeted
Police in Bangladesh have unearthed a mass grave they say contains an unspecified number of bodies.
Many of the corpses are fresh, police say, and are believed to be of people killed by forest bandits.
The discovery in southern Noakhali region comes after angry mobs in the area killed at least 27 suspected bandits over the last two days.
Correspondents say locals were taking revenge for what they say has been years of terror because of the bandits.
For years the villagers were living in a reign of terror unleashed by these criminals
Noakhali administrative head Mostafa Kamal Haider
Police had drafted in villagers to help them flush suspects out of their forest hide-outs.
But angry locals beat most of those caught to death. When police tried to stop villagers from carrying out the lynchings, they themselves were attacked.
It is unclear if those who died in the lynchings had anything to do with the mass grave. Police have found a number of skeletons, but also some corpses in an early state of decay.
Witnesses say the lynch mob attacks were frenzied and indiscriminate. Even children are alleged to have been targeted.
Relatives say those who died were innocent - none had been found guilty of any offence.
The killings were carried out on a group of islands, near the port of Chittagong, known locally as chars, that are heavily eroded by the sea.
Each year some chars disappear, while new ones are created. Criminals are known to take part in enforced land grabs.
Correspondents say the mob violence is the latest example of the breakdown of law and order in Bangladesh, where a poorly trained, ill-disciplined and under-staffed police force has struggled to cope.
Many people feel they have no option but to take the law into their own hands, correspondents say.