Unidentified gunmen stormed a retirement home run by Catholic nuns in the southern city of Aden yesterday shooting 16 people to death, including 4 Indian nuns, Yemeni security officials and witnesses said.

Two gunmen surrounded the home for the elderly in Aden while another four fighters entered the building, witnesses and officials said. They said the gunmen moved from room to room, handcuffing the victims before shooting them in the head. The officials spoke on condition of anonymity because they were not authorized to speak to the press.

One nun who survived and was rescued by locals said that she hid inside a fridge in a store room after hearing a Yemeni guard shouting "run, run."

Khaled Haidar told The Associated Press that he counted sixteen bodies, including that of his brother, Radwan. All had been shot in the head and were handcuffed. He said that in addition to the four Indian nuns, six Ethiopians, one Yemeni cook, and Yemeni guards were among those killed.

He said that his family was the first to arrive at the house and that he spoke to the surviving nun, who was crying and shaking. Haidar said that his family later handed her over to southern fighters in charge of security in the local Aden district, Sheikh Osman. The bodies were transferred to a police station and then a hospital run by the aid organization known as Doctors Without Borders or MSF. An official with MSF confirmed that 15 bodies had arrived at the hospital. Haider said his family took his brother's body for burial.

There are around 80 residents living at the home, which is run by Missionaries of Charity, an organization established by Mother Teresa. Missionaries of Charity nuns also came under attack in Yemen in 1998 when gunmen killed three nuns in the Red Sea port city of Hodeida.

Yemen's war has killed at least 6200 civilians and injured tens of thousands of Yemenis, and 2.4 million people have been displaced. DAESH and al-Qaida affiliates have exploited the lawlessness and created safe havens in the south. Al-Qaida controls several southern cities and DAESH has claimed responsibility for a wave of deadly attacks in Aden, including a suicide bombing that killed the city's governor and several assassination attempts on top officials. Aden's churches have also come under attack. In the summer, a Catholic church in the district of Crater was torched and sabotaged by extremists.