The ousted officials include the director of Tunisia's tourist police and the police chief for the neighbourhood around the National Bardo Museum, government spokesman Mufdi Mseddi told The Associated Press.
The decision was made after the prime minister visited the neighbourhood of the attack and noted security problems, the spokesman said. President Beji Caid Essebsi had also criticised security failings around last week's attack.
The Islamic State group claimed responsibility for attacking the museum, a trove of Roman mosaics and Tunisia's leading historical museum.