Yemeni security officials say a suicide bomber has killed at least 22 people at a police academy in the capital, Sanaa.
Officials said dozens more were wounded in the blast, which occurred as police cadets were leaving at the end of their school day.
There was no immediate claim of responsibility.
Al-Qaida linked militants seized several towns in the province of Abyan last year while the government was pre-occupied with a pro-democracy uprising against then-president Ali Abdullah Saleh. His successor Abed Rabbo Mansour Hadi launched a U.S.-backed military offensive in May to recapture those areas.
On May 21 the militants carried out a suicide bombing at a parade ground in Sanaa that killed 96 Yemeni soldiers.
Some information for this report was provided by AFP and Reuters.