SANAA, Yemen — During its modern history, Aden has represented a unique model for coexistence and tolerance, as it is the only city in Yemen housing citizens from all regions, religions and races. But its history has been put to the test like never before.

Since the Houthis and former President Ali Abdullah Saleh were expelled from Aden in July 2015, following 3½ months of bloody battles with forces loyal to President Abed Rabbo Mansour Hadi, who is backed by the Arab coalition forces, Aden’s openness has declined amid the takeover of extremist groups such as the Islamic State (IS), al-Qaeda and the Salafists.

On May 15, an anonymous armed man shot activist Amjad Abdul Rahman, 21, in the head, killing him instantly inside an internet cafe in Aden's Sheikh Othman district.

A close friend of Rahman’s told Al-Monitor on condition of anonymity for fear of jeopardizing his life, “Amjad was threatened by Salafists who accused him of atheism. They told him that his life would be at risk unless he repented.” Rahman was a member of a cultural club called Al-Nasieh, which was established by secular citizens and intellectuals in 2016. The club discusses religion and women’s rights, which extremists consider prohibited.