A bomb killed four policemen Wednesday in Yemen's second city Aden, where extremists have repeatedly targeted security forces, a security official said.
Another six officers were wounded in the blast in the southern port city where the Saudi-backed government has its base, the official told AFP.
Despite a 16-month-old Saudi-led military intervention, the government has struggled to secure the city.
On Friday, a suicide bombing claimed by Al-Qaeda hit the convoy of Aden governor Aidarus al-Zubaidi, wounding three people travelling with him.
The extremists also claimed two suicide bombings Monday that killed 11 people in two of their former strongholds in the southeast.
Earlier this year, the Saudi-led coalition launched a major offensive against Al-Qaeda, helping to recapture the Hadramawt provincial capital of Mukalla in April after a year of extremist rule.
Coalition forces had previously focused their guns on Shiite rebels and their allies who control the capital Sanaa and much of the north and centre, creating a power vacuum that the extremists exploited.
