The attack came just days before a meeting in London to discuss how to tackle the al-Qaeda movement in Yemen.
On Wednesday, ministers and officials from 21 countries will gather in London for for talks called after Al-Qaeda in the Arabian Peninsula claimed it had armed a Nigerian accused of attempting blow up a US-bound airliner on Christmas Day.
Elsewhere in southern Yemen on Sunday, at least two protesters were injured in clashes with security forces in the southern city of Dhaleh.
The violence reportedly broke out as the protesters, who were mainly students, demanded the release of a teacher who had been detained by the authorities for two months.
The latest unrest came after the so-called Southern Movement, a loose coalition of opposition groups, called for a six-hour general strike on Monday morning and demonstrations on Tuesday.
North and south Yemen united in 1990 under Ali Abdullah Saleh, the president, but ongoing grievances led to a brief civil war in 1994, which was won by the north.
Many southerners complain that state jobs and resources are unfairly distributed, favouring the north.