Lagos, Nigeria (CNN) The Nigerian Senate was on high alert Wednesday after armed men interrupted a session at Nigeria's parliament, stealing its mace.

The men were allegedly led by suspended lawmaker Ovie Omo-Agege who seized the symbol of authority from the upper legislative chambers sitting in Nigeria's capital Abuja, the Senate said.

The incident was branded "an act of treason" by Aliyu Abdullahi, a Senate spokesman who said the lawmaker was trying to overthrow a branch of the Federal Government of Nigeria.

VIDEO: How suspended senator, Omo-Agege ran away with the mace

Cc: @NGRSenate pic.twitter.com/nM41AOdexd — TheCable (@thecableng) April 18, 2018

"This action is an affront on the legislature," he said in a statement.

"Security agencies must stand on the side of due process and immediately mobilize their personnel to retrieve the mace and apprehend the perpetrators of this act," Abdullahi said.

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