The president, in a nationwide broadcast, said the decision was taken based on the advice of the Federal Ministry of Health and the Nigerian Centre for Disease Control, NCDC.
It was, however, unclear if the president consulted the National Assembly before shutting down states.
However, Senate spokesman Godiya Akwashiki said the President must have obtained legal advice before acting.
Akwashiki said: “Lagos has been locked down partially since a few days ago. It is not something to worry about. They should allow leaders to make decisions, especially in this type of crisis situation that we are faced with. I want to believe that the President must have consulted well.
“I want to assure you that if it is something that is constitutionally mandatory for the Senate to approve, we said it the other day when we took a break that the leadership had directed all Senators to be on standby in case of any emergency.
“If it needs the attention of the Senate, I want to assure you that for the betterment and safety of our own people, it will be done because that is the primary reason for which we are there.
“We are all working hard to see that we get out of this crisis. So there is no cause for alarm.”