Forces loyal to exiled president Abed Rabbou Mansour Hadi advanced on retreating rebels in the northern outskirts of Aden Sunday ahead of a humanitarian truce declared by the Saudi-led coalition, AFP reported.
Pro-government forces fought to tighten their hold on the southern port city and surrounding area before the ceasefire takes effect at midnight (2100 GMT).
Houthi rebel leader Abdulmalik al-Houthi released a statement on a Twitter account believed to be managed by his group claiming to have rejected the unilaterally declared truce, saying it was aimed at giving pro-government fighters a chance to regroup.
AFP was unable to contact Houthi representatives to confirm the statement.
Last week, pro-Hadi forces regained control of much of Aden from Houthi rebels after withdrawing from the city more than four months ago.