Lagos has seen shootings, looted shops and a prison set ablaze since security forces this week opened fire on peaceful protesters calling for better governance and an end to police brutality in the city of 20 million.
Amnesty International said Nigerian soldiers and police gunned down 12 demonstrators, while 56 have died overall across the country since a wave of protests began two weeks ago.
President Muhammadu Buhari warned protesters on Thursday not to “undermine national security” in his first national address since Tuesday’s incident, which he avoided mentioning directly.
Instead, he blamed agitators who he said had “hijacked and misdirected” the protest movement.
“Under no circumstances will this be tolerated,” Buhari added.
International condemnation has snowballed in recent days with the United States, African Union, European Union and Britain all criticising authorities for using excessive force.
US Secretary of State Mike Pompeo called for an immediate investigation into violence by security forces but Buhari has brushed off all foreign rebukes.