A number of people taking part in a protest against police brutality have reportedly been shot dead or wounded in Nigeria’s biggest city, Lagos.

Witnesses said up to 12 people were killed and others wounded when soldiers opened fire. Amnesty International said it had “credible reports” of deaths.

The state governor said about 25 people had been wounded but denied there were any fatalities.

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 protesters 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.

President Muhammadu Buhari has appealed for “understanding and calm”.

Witnesses spoke of uniformed men opening fire in the wealthy Lekki suburb on Tuesday evening.

Soldiers were seen barricading the protest site moments before the shooting, BBC Nigeria correspondent Mayeni Jones reports.

Social media footage streamed live from the scene shows protesters tending to the wounded.

An unnamed witness told BBC News that shortly before 19:00 local time soldiers “pulled up… and they started firing directly” at peaceful protesters.

“They were firing and they were advancing straight at us. It was chaos. Somebody got hit straight beside me and he died on the spot,” he said.

Four witnesses told Reuters news agency soldiers had opened fire on demonstrators. One of them, Alfred Ononugbo, 55, said: “They were firing into the crowd. I saw the bullet hit one or two persons.”

The Premium Times newspaper quoted witnesses as saying about 12 people had been killed.

In a tweet, Amnesty International Nigeria said it had “received credible but disturbing evidence of excessive use of force occasioning deaths of protesters at Lekki toll gate in Lagos”.

Amnesty International spokesman Isa Sanusi later said: “People were killed at the tollgate by security forces… we are working on verifying how many.”

How have the authorities reacted?

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.

(BBC)