One in seven women live in poverty. (File photo: Reuters)

Millions of widows worldwide suffer crushing poverty and persecution, their numbers swelled by a proliferation of conflicts from Syria to Myanmar.

International Widows' Day on June 23 aims to raise awareness of the often hidden injustices they face.

Many are robbed of their inheritance, while others are enslaved by in-laws, accused of witchcraft or forced into abusive sexual rituals.

Here are some facts:

- Experts estimated there were 258.5 million widows globally in 2015, but say the number is likely to have risen.

- Deaths through conflict and disease contributed to a 9 percent increase in the number of widows between 2010 and 2015.

- The biggest jump has been in the Middle East and North Africa, where the estimated number of widows rose 24 percent between 2010 and 2015, partly due to the Syrian war and other conflicts.

- One in seven widows globally - 38 million - lives in extreme poverty.

- One in 10 women of marital age is widowed. The proportion is about one in five in Afghanistan and Ukraine.

- A third of widows worldwide live in India or China. India, with an estimated 46 million widows in 2015, has overtaken China (44.6 million) to become the country with the largest number of widows.

- Widow "cleansing" rituals in some sub-Saharan countries may require a widow to drink the water used to wash her dead husband's body or to have sex with an in-law, village "cleanser" or stranger.

- Campaigners for widows' rights say such rituals, which are intended to rid a widow of her husband's spirit, spread disease and are a violation of dignity.

- Widows are regularly accused of killing their husbands either deliberately or through neglect - including by transmitting HIV/AIDS - in India, Nepal, Papua New Guinea and sub-Saharan Africa.

- Property seizures and evictions by the late husband's family are widespread in many places including Angola, Bangladesh, Botswana, India, Ivory Coast, Ghana, Kenya, Malawi, Nigeria, Tanzania and Zimbabwe.

- A significant number of girls are widowed in childhood - a reflection of the prevalence of child marriage in developing countries and the custom of marrying off young girls to much older men.