The Southern Transitional Council was created in May 2017. The governor of Aden Aidarus al-Zoubaidi, dismissed from his office on 27 April 2017 by Yemeni President Abdrabbuh Mansur Hadi, became its leader.[31][32]
The Southern National Assembly, made up of 303 members from every southern province, held its first parliamentary session in Aden on 26 December 2017.[33]
Amid tensions between the UAE-backed Southern Transitional Council and the Saudi-backed Hadi government in Aden, the STC announced on 21 January 2018 that it would overthrow the Yemeni government within a week unless President Hadi sacked his entire cabinet, including Prime Minister Ahmed Obeid bin Daghr for corruption.[34][35] The STC also declared a state of emergency until its demands were met.[36] The government responded by banning protests in Aden, but the STC organised an anti-government rally for 28 January 2018.[37]
Gun battles erupted in Aden on 28 January 2018 when security forces loyal to the Hadi government attempted to prevent pro-STC demonstrators from entering the city.[38] Districts reportedly affected by the fighting included Khormaksar, al-Mansoura, and Dar Sad, with protests taking place in al-Orouth square. Pro-STC forces were reported to have seized a number of government offices, including the Hadi government's headquarters.[9][34][38]
The STC captured the government headquarters in Aden.[39][40] The government also ordered its own troops to return to base, following fierce clashes across Aden. The fighting subsided by the evening after Prime Minister Daghr ordered a truce and instructed forces loyal to the government to return to barracks, witnesses said.[41] In the night, the fighting continued.[42][43]
New fighting broke out after a brief ceasefire on the day before it collapsed.[44][45][46] The STC sent reinforcements from Dhale and Shabwah provinces to Aden.[30][47][48] Tank and heavy artillery battles were also fought that day, killing five STC fighters and four Yemeni government soldiers.[14][49][50] The Presidential Forces led by Brigadier General Abdullah al-Subaihi began shelling Mount Hadid, which overlooks the 1st brigade for Security Belt Forces and is run by Major General Aidarus al-Zoubaidi.[51] The two sides deployed tanks and began shelling one another in Khormaksar district, where snipers were on the roofs of buildings.[52] The fighting moved into Crater district, and schools were closed for a second consecutive day.
The STC would go on to proclaim victory on the 30 January.[53]
The members of the Hadi-government present in Aden, including the Prime Minister, were surrounded in the Presidential Palace and "de facto under house arrest"[59][60][61][62] but the STC did not enter the palace.[63][64] Yemen's prime minister prepared to flee the country for Saudi Arabia after the STC seized the area around the presidential palace in the southern city of Aden in fierce battles overnight.[59][65][66]
The charity Save the Children suspended humanitarian work in the city due to the fighting.[67]
The STC seized the Dar Sad District, which was the last pro-Hadi stronghold, having captured the Crater and Tawahi districts earlier.[68] Residents have said that the STC captured most of the city by day's end.[69]
On the 31 January, separatists took the office of the prime minister's secretary, but fighting no longer took place.[70] The government and the STC exchanged prisoners after the fighting.[71]
Yemen – Prime Minister Ahmed Obeid bin Daghr stated that "a coup is ongoing here in Aden against legitimacy and the country's unity,"[72] and asked Saudi Arabia for military support.[9]
Yemen – President Abdrabbuh Mansur Hadi ordered his forces to cease fire immediately after fierce clashes with southern separatists broke out in Aden.[73] On 30 January Hadi called the clashes "nothing short of a coup".[20]
Southern Transitional Council – The Vice President of the STC Hani bin Braik blamed Hadi's government for the fighting in a Twitter post: "They forced us to put on our military uniforms, although we told them we were non-violent. But we were ready."[74] On 22 January, Aidarus al-Zoubaidi accused the Hadi and Daghr-led government of "rampant corruption".[34]
Southern Transitional Council – The president of the STC Aidarus al-Zoubaidi declared a state of emergency in Aden and that "the STC has begun the process of overthrowing Hadi's rule over the South".[47] On 30 January Aidarus al-Zoubaidi via France 24 announced full military cooperation between his forces and Tareq Saleh to liberate the remaining northern strongholds.[75][76]
France – France's Foreign Ministry expressed concern over the fighting and urged both sides to negotiate.[77]
Saudi Arabian-led coalition called everyone involved to hold back. The protests in Aden were an invitation to turn down mistakes in government work.[78]
This list includes World War I and later conflicts (after 1914) of at least 100 fatalities each Prolonged conflicts are listed in the decade when initiated; ongoing conflicts are marked italic, and conflicts with +100,000 killed with bold.