At least four Asian elephants have been killed in Bangladesh over the past week, officials said Sunday, putting the dwindling population of the endangered creatures at further risk.

Fewer than 100 elephants remain in the South Asian country, where they come into regular conflict with humans as their territory shrinks.

"Four elephants died in Chittagong division alone since last week," forest department official Rafiqul Islam Chowdhury told AFP.

He said two had been electrocuted and a third was shot in a forest reserve, while another had died of "natural causes".

A fourth elephant also died by electric shock in northern Sherpur near the Indian border, police there said.

For generations, the Chittagong hills have been used by elephants as a route for migrating back and forth from neighbouring Myanmar.

But farming, and refugee camps housing about a million Rohingya refugees from Myanmar have reduced their territory and led to growing numbers of deaths -- both of elephants and people.

Twelve elephants have been killed across Bangladesh in the past 18 months.

Farmers use live electric wires along their perimeters to keep out grazing elephants, which Chowdhury said was a big threat to their survival.

Raquibul Amin of the International Union for Conservation of Nature said that illicit farming in forested areas was partly to blame for the killings.

But in recent times the biggest threat to the survival of elephants are the refugee camps which are located in the middle of the elephant’s route for migrating back. A number of elephants have died in recent times near the camp area.