Security officials have said that a suicide bomber has killed at least 25 persons and injured 54 in an attack which targeted police recruits at a security compound in the southern Yemen city of Mukalla, Al Jazeera reports.
The officials spoke on condition of anonymity on Sunday because they are not authorized to speak to the media.
Some of the victims were policemen returning to work following last month's recapture of Mukalla by forces of the internationally recognised government.
Other victims included young men applying for jobs with the city's local police.
The Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group has claimed the attack, the second but rare intervention by the group in an area known as a stronghold of rival al-Qaeda.
On Thursday, 15 Yemeni troops were killed in attacks on army positions outside Mukalla. ISIL said one of its fighters blew up a vehicle packed with explosives in an army base in Khalf district on the city's eastern outskirts.
The port city has been held for more than a year by Yemen's local al-Qaeda affiliate, Al-Qaeda in the Arabian Peninsula (AQAP).
The US regards AQAP as its most dangerous and has stepped up a longstanding drone war against it in recent weeks.
But armed groups retain a strong presence and still control several towns in the interior valley of Wadi Hadramawt.
The Yemen conflict has killed more than 6,400 people and displaced 2.8 million since March last year.