Clashes resumed Sunday after a short period of calm overnight in the central Mansura district, a stronghold of jihadists.
Warplanes and Apache helicopters from a Saudi-led coalition have carried out air strikes in support of security forces, security sources said.
‘At least 17 Al-Qaeda fighters and two policemen have been killed since Saturday,’ a security official told AFP, adding that most of the jihadists were killed in air raids.
Dozens of gunmen in balaclavas carrying the Al-Qaeda flag deployed to push back police trying to enter the neighbourhood, witnesses said Saturday.
The police said in a statement that fighting against the ‘armed terrorist gangs in Mansura will continue to ensure the safety of residents’ in Yemen's main southern city.
Al-Qaeda and the Islamic State group have taken advantage of the conflict between Iran-backed Houthi insurgents and pro-government forces to reinforce their presence in the south, including in Aden.
More than 6,100 people have died -- half of them civilians -- since the coalition launched air strikes against the rebels and their allies in March 2015, according to the UN.