Two car bombs exploded at two military checkpoints west and east of al-Mukalla, the official told Anadolu Agency.
“Six soldiers were killed and 30 people injured, including civilians,” the official said, requesting anonymity due to restrictions to speaking to media.
There has been no claim of responsibility for the attacks.
In April, Yemeni army forces, backed by Saudi-led coalition warplanes, recaptured al-Mukalla, the provincial capital of Hadhramaut province, from al-Qaeda group.
Last month, at least 48 government forces were killed in multiple suicide bombings claimed by Daesh militants in the southeastern city.
Yemen has suffered violence and chaos since September 2014, when the Houthis and allied forces loyal to former President Ali Abdullah Saleh overran capital Sanaa and several other provinces, forcing President Abd Rabbuh Mansour Hadi and his government to temporarily flee to Riyadh.
In March of last year, Saudi Arabia and its Arab allies launched a massive air campaign in Yemen aimed at reversing Houthi gains and restoring Hadi’s embattled government.