By Subir Bhaumik BBC News, Calcutta

Bhutan says the refugees in Nepal are illegal immigrants

The refugees are demanding India allow them to go back to Bhutan via West Bengal's border with Nepal.

One refugee was killed and more than 20 injured when Indian police fired on them when they tried to enter India.

Nepal is home to about 107,000 ethnic Nepalese expelled from Bhutan, which says they are illegal immigrants.

The UN High Commissioner for Refugees Antonio Guterres recently urged the Bhutanese government to repatriate them.

Divided

Since Tuesday, thousands of refugees have been trying to cross the Mechi river that marks the border of West Bengal state with Nepal.

Indian police say at least six of their men were injured when the refugees pelted them with stones on Tuesday.

Violence has also continued for a third day in some refugee camps in Beldangi in eastern Nepal, where large numbers of Bhutanese refugees oppose UN plans to settle them in Western countries.

They beat up some of their own leaders who support third-country settlement in the US, leading to intervention by the Nepal police.

Two refugees were killed in Beldangi when police fired shots over the weekend.

After nearly two decades in the camps of Nepal, the Bhutanese refugees are divided.

Some accept a future in the West; others are determined to go back and enrol as voters in Bhutan ahead of next year's parliamentary elections in the Himalayan kingdom.

But India says it is determined to stop them in view of Delhi's cordial relations with Bhutan.

It is one of Asia's most protracted refugee problems.

Forgotten by most of the world, the refugees are dependent on UN food rations and officially forbidden to work in Nepal.