By Jill McGivering BBC South Asia correspondent

The world's first international conference on widows in South Asia is designed to highlight the suffering of women who are often excluded and marginalised.

India alone has almost 40 million widows.

Traditionally Hinduism frowns on widows remarrying and many have their social and economic power eroded too - although in recent years many widows have benefited from moves to enhance their status.

We treat widowhood not as a natural stage in the life cycle of a woman, we treat it as some kind of an aberration

Conference organiser Meera Khanna

Vrindavan is a pilgrimage town now home to thousands of destitute widows.

Ashtabala Mundo is one of thousands of widows who have been driven by poverty to the holy town.

She was married off when she was still a baby and widowed when she was still a child.

"We have to come and sing here morning, noon and night and for all that I only get is $10 a month," she said.

"By the time I've paid the rent, I can't afford to buy cooking oil. So I often go all day without a hot meal," Mrs Mundo said.

On the sidelines

The women line up, after singing for several hours, to receive a cup of rice and a few teaspoons of lentils. It isn't much.

Ahstabala Mundo: Widowed when still a child

In India, widows are an invisible community.

Meera Khanna, one of the conference organisers, says although many widows are treated less harshly nowadays, they still face discrimination and neglect.

"We treat widowhood not as a natural stage in the life cycle of a woman, we treat it as some kind of an aberration. We accept death but we don't accept widowhood," she said.

"Because somewhere in the Indian psyche, the woman's identity is with the man and the minute he's not there, it's something that cannot be accepted."

Mr Madhav of Vrindavan's Shri Bhagwan Bhajan Ashram temple society says more than a thousand widows a day come to his temple alone.

"Most of them are very poor and once their husbands die, they have to come here. We can at least give them food and clothes."

Sad tales

Outside, loudspeakers play songs honouring Lord Krishna, in the town associated with the Hindu God.

I've been too ill to sing at the temple for the last three days so I haven't had a thing to eat

Nirmala Dasi, 85

Many of the widows who flock here have nowhere else to go.

Hindu widows are not supposed to remarry. With little social or economic status, many become destitute.

We met Nirmala Dasi, a frail 85-year-old, begging at the temple gate.

When she spoke, she dissolved into tears.

Some sing at local temples in order to get food

"I've been too ill to sing at the temple for the last three days so I haven't had a thing to eat. You don't get anything unless you go there."

We were soon surrounded by widows with sad stories to tell.

"I spend almost everything I get on a room I share with four others. I've no relatives, or I wouldn't be here," said Mithila.

"It's so cold here, I'm always freezing."

Widows have been a marginalised and deprived group for generations.

This conference aims to highlight their suffering - and stop so many women from losing their dignity and basic rights when they lose their husbands.