This curfew is aimed to implement social distancing, and encourage people to stay home from 7 p.m. to 5 a.m local time (2000 GMT to 0600 GMT) during the holly month of Ramadan which begins in Morocco on Saturday.
The ministry said in a statement that it is strictly forbidden for citizens to go out of their homes, except for the people working in vital sectors.
Public authorities will continue to reinforce control operations across the country to ensure the strict implementation of the curfew, the statement added.
Morocco has extended till May 20 a public health emergency, which has restricted movements, and banned private and public means of transport between cities.
Since then, citizens could only leave their homes if they are provided with special authorization from local authorities.
The new measures came amid fears of a major breach of the state of medical emergency during the month of Ramadan.
A total of 57,003 people have been arrested so far in the Moroccan cities, 30,689 of whom were charged with breaching the state of medical emergency.