Aden: Unidentified gunmen on motorbikes shot dead two leaders of the loyalist militia controlling the southern Yemeni port of Aden in separate attacks on Monday, officials said.

Rasheed Khaled Saif and Hamdi Al Shutairi were military leaders of the Popular Southern Resistance, a loose alliance which fought the siege of the city by Al Houthi militia forces with support from Gulf Arab states.

No group immediately claimed responsibility for the killings, which followed the shooting of a senior security official in Aden on Sunday.

Groups loyal to exiled President Abd Rabbo Mansour Hadi, who is currently based in Saudi Arabia, recaptured Aden in July.

Since then, a power vacuum has grown, with Al Qaida militants moving into a main neighbourhood and unknown assailants blowing up the intelligence headquarters.

Residents have complained that police have largely quit the streets.

“We finished the war and Al Houthis, but this series of assassinations is really worrying us. There’s a security vacuum, the people hope some kind of authority can be established and the police will be deployed so we can be put at ease,” said local construction worker Mohammad Ahmad Salem.

The northern-based Al Houtis seized the capital Sana’a in September 2014 then took control of much of the country.

Loyalist forces, supported by air strikes from a Saudi-led coalition, have made significant advances since July however.

Gulf states see Al Houthis as a proxy of their archrival Iran, while the group says it is fighting a revolution against corrupt officials beholden to the West.