The Islamic State affiliate in Yemen claimed responsibility for yesterday's attack in a statement posted by the group's supporters on Twitter. It was not possible to verify the claim.
Witnesses said firefighters and ambulances rushed to the scene in the busy district of Crater. Body parts were scattered on the ground. Officials said eight people were injured.
The officials spoke on condition of anonymity because they were not authorised to speak to the press.
The checkpoint was manned by policemen and policewomen after authorities received tips that IS militants are disguising themselves as women.
IS has claimed responsibility for some of the deadliest attacks in Yemen since March, including the assassination of a city governor and the bombing of a hotel that formerly housed the Cabinet.