Ike Ekweremadu, deputy senate president, gave the ultimatum after a delegation of the house of representatives visited the senate on Wednesday afternoon.
The mace was stolen after Ovie Omo-Agege, lawmaker representing Delta central senatorial district, invaded the chamber with suspected thugs.
Omo-Agege was suspended last week for challenging the sequence of election as proposed by the senate.
He had said it was targetted at President Muhammadu Buhari.
However, he made his way into the red chamber on Wednesday while some unidentified persons who accompanied him carted away the mace.
In a statement, Abdullahi Sabi, spokesman of the upper legislative chamber, said the act is tantamount to treason.
“Today, some hoodlums led by suspended senator, Ovie Omo-Agege, walked into the senate plenary and seized the symbol of authority of the upper legislative chamber, the mace,” he said in a statement.
“This action is an act of treason, as it is an attempt to overthrow a branch of the federal government of Nigeria by force, and it must be treated as such.
“All security agencies must stand on the side of due process and immediately mobilise their personnel to retrieve the mace and apprehend the mastermind and the perpetrators of this act.
“This action is also an affront on the legislature, and the leadership of the house has come to express their support against this action.
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