A young man from Aden in Yemen has been abducted and murdered, possibly for apostasy, after he wrote posts on social media that appeared to criticise extremism in Islam.
Sources close to his family said reports that he had been murdered for atheism could not be accurate because they insisted he was not an atheist.
Omar Mohammad Bataweel was shot dead after he wrote some posts that seemed critical of Islam on Facebook.
Even after his death, many of the comments on a Facebook page dedicated to Bataweel condemned his atheism.
However, there was also shock and outrage among Muslims and others.
The Nobel Peace Laureate Tawakkol Karman, from Yemen, said on Facebook: "The murder of Omar Mohamed in Aden because of apostasy is a heinous terrorist crime and will be repeated if not combated and atoned for. The local authority and the government must prosecute and put on trial the perpetrators of this crime."
The Al-Bab blog reported that he was seized near his home on Sunday and his body found the next day.
Apostasy is punished with the death penalty in Qatar, Saudi Arabia, Sudan, the United Arab Emirates and Yemen.
Often, those who renounce Islam are allowed to flee the country or are tried and put in prison for a different crime to avoid interntational embarrassment, Al-Bab said.
The blog cotinued: "In the eyes of Islamist militants, however, these governments are neglecting their religious duty, and the result is vigilante killings. Such killings may be inspired by the actions of groups like IS but they are also legitimised by national laws against apostasy and by governments which reject the right to freedom of belief."
Al-Bab cites one leaflet, headed: Notice to Atheists.
It states: "To every atheist who reviles and incites hatred of Islam in social media: Your end is to choke to death, to perish as an animal perishes, to be cast under dirt and mud and have worms eat your rotten body. No one will remember you; it will be as if you never existed ..."
It ends with the words: "Islam will remain until the Day of Judgment."
A local freelance journalist, Fuad Rajah, told Christian Today: "There is no evidence, confirmation or reliable information Omar Bataweel was abducted by Islamists and killed for atheism apostasy. His family declined to comment and I have sought other sources, friends or others, but no one showed cooperation.
"According to activists and journalists in Aden people are afraid to get killed or harmed if they say something because Jihadists and extremists are everywhere in Aden.
"It is very weird and no one can prove he was killed for atheism. Nonetheless, it is still possible he was murdered by extremists amid security vacuum and presence of Islamists in Aden. By the way, his posts and thoughts did not indicate he was atheist. He just was criticising extremism like we all do. Maybe he was in the wrong place at the wrong time."
Recently in Saudi Arabia, a Palestinian poet who had been sentenced to death for apostasy had the penalty cut to eight years in prison and 800 lashes.