A bus carrying Yemeni air force personnel was bombed as it traveled in the capital Sanaa on Sunday.
The bus was traveling near an air force base when a bomb exploded on the vehicle - likely having been planted there.
The bombing was believed to be the work of Al Qaeda in the Arabian Peninsula (AQAP), which has been targeting soldiers in a campaign to destabilize the government.
More than 90 Yemeni soldiers were killed in May when a suicide bomber blew himself up at an army parade.
In early August, the United States closed its embassies around the Middle East after threats of imminent violence from AQAP.
The United States has been battling militants using drone strikes in southern and central Yemen.
The US has launched 18 drone strikes against militants since January.
It is believed that AQAP's top leadership remains alive despite the strikes.