Three suicide bombs have targeted checkpoints in the southern Yemeni city of Aden, killing at least 26 people, residents and eyewitnesses said.
The Islamic State of Iraq and the Levant (ISIL) group claimed responsibility for Friday's attacks, which coincided with the first anniversary of the start of civil war in Yemen.
In one of the blasts, a vehicle exploded as it arrived at a military checkpoint in the Buraiqa area in northwestern Aden, killing soldiers and civilians, eyewitnesses and security sources said.
The other two bombings hit checkpoints on the road to a base used by the military coalition that is fighting in Yemen.
Medical officials said that the death toll is expected to rise and that there were women and children among the victims, but did not give numbers for civilian casualties.
Analysis: Beyond the fragile peace in Aden
A Saudi-led military coalition entered Yemen's war a year ago to try to prevent Iran-allied Houthi rebels and forces loyal to ex-President Ali Abdullah Saleh from taking control of the country.
Other armed groups like ISIL and al-Qaeda's local wing have thrived in the chaos.
Fighters loyal to Yemen's president Abd-Rabbu Mansour Hadi and coalition troops recaptured Aden from Houthi forces in July.
But frequent violence has continued into this year, including suicide bombings, in the city of one million people.