A 27-year old woman was beaten, kicked and burned to death in public in the Afghan capital Kabul on Thursday, after she was apparently caught setting fire to a copy of the Koran.
Video footage shows the woman, identified only by her first name as Farkhunda, being lynched by a large group of men near the Shah-e Don Shamshira shrine and mosque in the centre of Kabul.
The woman’s parents said Farkhunda has been suffering from mental illness since she was 11.
The men surrounded Farkhunda and are shown to be kicking, jumping and stamping on her, while dozens of onlookers film the footage on their smartphones amid cries of "Allahu Akbar" ("God is greatest").
Farkhunda is then seen being beaten with wooden poles and was shown attempting to resist her killers as she was dragged on to a rooftop and subsequently thrown off into a nearby dry river bank. She was then set alight. Her charred remains were subsequently found at the site.
At least four people are said to have been arrested in connection with the killing, according to the country’s interior ministry.
But a spokesman for the country’s religious affairs ministry said that in certain circumstances the killing would have been legal.
“If this woman was against the holy Koran and had done it deliberately, and if she was at the same time a non-Muslim woman, then we would justify the action of the people,” said Abdul Rahman Ahmadzai.
The incident comes as Ashraf Ghani, president of Afghanistan, was due to arrive in Washington DC on Sunday to embark on his first visit to the US since assuming office in September 2014.
Mr Ghani has called for an investigation into the killing, which was widely condemned internationally.
In his meetings with the Obama administration, Mr Ghani aims to secure a commitment of military and financial support from the US, which he says would help the fight against the Taliban, Islamic State of Iraq and the Levant affiliates and insurgent groups which continue to spread in Afghanistan.
US and Nato combat troops withdrew from Afghanistan in 2014 leaving behind some 13,000 foreign personnel - almost 10,000 of whom are American - in largely training and advisory roles.
The Pentagon originally planned to withdraw another 5000 by the end of this year but, with insurgents on the offensive and with improving ties with Kabul, has hinted it will leave troops in place for longer.
According to the UN, 2014 was the deadliest year for Afghan civilians since records began in 2009.
The 65-strong Afghan delegation will meet John Kerry, Secretary of State, on Sunday and will visit the Pentagon, before travelling to Camp David.