Nigeria's police chief has ordered the immediate mobilisation of all force resources to control the worst street violence in two decades, stemming from protests against police brutality.
The unrest, unprecedented since the 1999 return to civilian rule, is the most serious political crisis confronting President Muhammadu Buhari, a former military ruler elected in 2015.
Violence, particularly in the commercial capital Lagos, escalated after demonstrators were shot on Tuesday night in the city's Lekki district during a round-the-clock curfew.
Witnesses blamed soldiers.
Rights group Amnesty International said soldiers and police had killed at least 12 protesters in two districts, though the army has denied soldiers were in Lekki.
Several states, mostly in southern Nigeria, have imposed curfews after two weeks of confrontations between security services and protesters.
The Nigeria Police Force said in a statement its inspector general Mohammed Adamu had ordered the immediate deployment of all assets and resources to end violence, looting and destruction of property by criminals masquerading as protesters.
Lagos state eased curfew restrictions on Saturday to 6pm-8am local time.
Workers took to streets to sweep away broken glass while cars again filled the roads.
Mr Buhari appealed to those taking part in widespread demonstrations to "resist the temptation of being used by some subversive elements to cause chaos".
Nigeria's President warned protesters not to 'undermine national security'. Source: AP
"For you to do otherwise will amount to undermining national security and the law and order situation. Under no circumstances will this be tolerated," he said in a televised speech last week.
But he failed to make any direct mention of the incident that has helped unleash chaos in Africa's biggest city and fuelled popular ire.
The president shrugged off condemnation from the US, African Union, European Union and Britain over the excessive use of force by the authorities.
"We thank you and urge you all to seek to know all the facts available before taking a position or rushing to judgment and making hasty pronouncements," the president told the international community.
