By Aziz El Yaakoubi
DUBAI (Reuters) - A gunman paused for a moment after entering an internet cafe in the Yemeni port city of Aden, approached Amgad Abdulrahman and pulled the trigger three times.
As the 22-year-old law student -- a member of a cultural club set up by secularists -- lay dying, the gunman waved his pistol threateningly before retreating outside. He then walked away without a word.
No group has claimed responsibility for the May 14 killing in broad daylight in the Sheikh Othman neighborhood, a brazen attack even for a city gripped by lawlessness more than two years into a civil war.
Friends suspect Abdulrahman was shot dead by Islamist militants who they say are waging a campaign of persecution against secularists accused of promoting an anti-Islam message or being atheists.
Some residents fear the killing has taken the persecution to a new level, nearly two years after local fighters backed by a Saudi-led coalition drove Iran-aligned Houthi forces out of the southern city.
Aden's governor, Abdulaziz al-Muflehi, chief of the local security forces and the city's police spokesman did not answer calls from Reuters to comment on the case.
But soldiers from a local security force comprising Salafist Islamists prevented the body being buried in the city cemetery.
"They said he was not a Muslim," said a friend of Abdulrahman who requested anonymity for fear of being targeted.
"His family had to take him to another cemetery far away from the city," she told Reuters.
Yemen has been torn apart by the civil war pitting the Houthis against the government of President Abd-Rabbu Mansour Hadi, which is backed by the Saudi-led alliance.
Although secularists have complained of harassment elsewhere in the country, they have not previously reported that anyone has been killed over their secularist beliefs.
Abdulrahman was a member a cultural club that was set up by secular students and intellectuals in 2016 and quickly came under pressure for broaching taboo subjects in public debates such as religion, women's rights and literature.
A few weeks before he was killed in Sheikh Othman, a lower middle-class residential area where low concrete buildings and houses flank dusty roads, Abdulrahman had helped moderate a debate hosted by the club known as al-Nassiya, on "the conditions of Adeni woman" in recent generations.
The debates proved divisive in Aden, once the cosmopolitan capital of the Marxist People's Democratic Republic of Yemen, a country that merged with more traditional north Yemen in 1990.
The identity of the club's opponents are not obscure, but hardline anti-Western groups al Qaeda and Islamic State have taken advantage of the civil war to press their own agenda in southern Yemen.
Abdulrahman had been detained at a military base by a military commander and accused of being an atheist last December. He was freed days later, but friends say the incident convinced the family to suppress their grievances.
"The family cannot even think about going to some kind of authority or seek justice for him," Abdulrahman's friend said.
Another member of the club, Mohammed Ali, said someone had also attempted to kill him on Dec. 29 last year. He now lives abroad.
"It started when imams in Aden mosques talked about us publicly, called us infidels and accused us of spreading atheism," said Ali.
Others were jailed, according to a statement issued by the club after Abdulrahman's killing, and some residents fear religious extremists have infiltrated the southern security forces to destabilize Aden.
Ali said he had received threats via social media and phone calls after publishing a book on Islam and science, in which he sought to argue that some assertions in the Koran, the Muslim holy book, were "scientifically wrong".
"In a dark street, a man came out of a car and shot at me twice," said Ali. "I still don't know how he missed me."
(Editing by Sami Aboudi, William Maclean and Timothy Heritage)