A number of people have reportedly been shot dead or wounded at a protest against police brutality in Nigeria's biggest city, Lagos.
Witnesses and the rights group Amnesty International said several people were killed and wounded when soldiers opened fire.
The state governor said about 25 people had been wounded but only one person had died.
An indefinite 24-hour curfew has been imposed on Lagos and other regions.
Protests over a now-disbanded police unit - the Special Anti-Robbery Squad (Sars) - have been taking place for two weeks, with demonstrators using the social media hashtag #EndSars to rally crowds.
As tensions continued to rise on Wednesday, police in different districts of Lagos fired shots in the air to disperse people defying the curfew, the BBC's Nduka Orjinmo reports from the capital, Abuja.
Protesters who briefly gathered again at the Lekki toll gate - where Tuesday's shootings took place - were forced out by police, he adds.
In a statement on Wednesday, President Buhari did not directly refer to the shootings, but called on people to have patience as police reforms "gather pace".
A statement issued by his office said the dissolution of the Sars was "the first step in a set of reform policies that will deliver a police system accountable to the Nigerian people".
"The presidency wishes to reiterate the full commitment of the Buhari administration to the implementation of lasting police reforms in Nigeria," it added.
The army has not issued a statement on events in Lekki, but in several Twitter posts it described media reports as "fake news".
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