At least five Yemeni soldiers were killed Tuesday in a bomb attack in the government-held southern city of Aden that was claimed by the Islamic State extremist group.
The attack came two days into a shaky ceasefire between mainly Shiite Houthi rebels and a coalition, led by neighbouring Saudi Arabia, that backs President Abd Rabu Mansour Hadi.
There were conflicting accounts of the attack. Security officials, who spoke on condition of anonymity, said a suicide bomber blew himself up amidst the troops. Islamic State's Aamaq news agency said an explosive device was used.
Tuesday's bombing is the latest security breach in Aden, which Hadi has declared his temporary capital because Sana'a is controlled by the Houthis.
Hadi loyalists and allies, backed by Gulf troops, have pushed the Houthis out of Aden and other areas in southern Yemen since the Saudi-led coalition began airstrikes against the rebels a year ago.
But they have been unable to prevent activity by jihadist groups behind their lines, with the Yemeni branch of al-Qaeda seizing wide areas of the southern Abyan and Hadhramaut provinces.
The recently formed Yemeni branch of Islamic State has also claimed deadly attacks on mosques in Sana'a.
UN-brokered peace talks between the Houthis and Hadi's government are due to start on April 18 in Kuwait.