The Federal Capital Territory (FCT) Abuja, Lagos and Ogun States are affected.
The Nigerian leader made the initial lockdown announcement in a national broadcast on Sunday, March 29.
But legal practitioners and critics condemned his “unilateral action”, arguing that it had to have legal backing.
Within 24 hours, Buhari signed the order and the matter was laid to rest.
Meanwhile, the Inspector General of Police, M.A Adamu, has ordered deployment of additional intelligence and operational assets of the Force to Lagos and Ogun.
This followed recent activities of hoodlums and street urchins.
Police Mobile Force (PMF) Units, Federal Special Anti-Robbery Squad (FSARS), Intelligence Response Team (IRT) and the Special Tactical Squad (STS) are now in the two states.
A statement by Force spokesman, Frank Mba, explained that they will strengthen security and bolster public confidence in the affected areas.
The Intervention Team is being coordinated by Deputy Inspector General of Police, DIG Peter Babatunde Ogunyanwo.