Sana’a: Yemeni security and medical officials say a suicide bomber has killed two pro-government fighters at a checkpoint in the southern port city of Aden.

The officials say the attack was in Aden’s Mansoura neighborhood.

It followed the Sunday storming of a supermarket by extremist militants, who fired shots into the air and briefly took hostages, according to security officials and witnesses.

Witnesses said the attackers warned supermarket employees against the mingling of men and women and demanded that female employees cover their faces.

Meanwhile, radical Islamist gunmen have threatened to use force against university students in Yemen’s southern city of Aden if they do not observe segregation of the sexes on campus, witnesses said.

Students said armed militants distributed leaflets containing the threats and signed by the Daesh terror group in at least three departments of the university of Aden.

The leaflets also banned music and demanded that students perform collective prayers on campus, they added.

They set a Thursday deadline for the demands to be met.

Otherwise they threatened to carry out car bomb and petrol bomb attacks.

The authenticity of the leaflets signed by the Aden and Abyan branch of Daesh could not be immediately verified.

Southern fighters allied with President Abd Rabbo Mansour Hadi and supported by Saudi-led coalition forces managed in July to push Al Houthi rebels out of the port city of Aden.

But extremist militants, including Al Qaida and Daesh, appeared to have gained ground in Yemen’s second city, where the radicals are now visibly present.

Al Qaida, active across several parts of Yemen, has exploited the collapse of central authority during a 2011 uprising that ousted veteran president Ali Abdullah Saleh.