One year ago, Adebanjo Akinwunmi gleefully waved a Nigerian flag at the Lekki Toll Gate, a stretch of tarmac in front of toll booths on a highway on the outskirts of Lagos. Joined by thousands of his countrymen, he demanded an end to what demonstrators said was endemic police brutality.

But the ebullient protests, which had taken place in cities across the nation of some 200 million, ended at the toll gate in a hail of gunfire.

Demonstrators said soldiers and police opened fire on Oct. 20, though both denied using live rounds. Rights group Amnesty International said 12 protesters were killed in two districts that night, triggering the worst street unrest since Nigeria returned to civilian rule in 1999.

At the toll gate on Wednesday, police forcibly dispersed hundreds of protesters in vehicles and dozens on foot who tried to mark the anniversary of the shooting, firing tear gas and detaining at least five, according to Reuters witnesses.

The largely peaceful protesters waved Nigerian flags and held placards reading: "Say no to oppression".

Police slapped one man as he resisted efforts to bundle him into a security vehicle, and another man inside had visible wounds to his head.

Dozens were also marching in Abuja, the capital, amid a heavy police presence.

The government has never acknowledged the extent of the violence. But it has promised to transform policing, including meeting the demonstrators' demand to shut down the Special Anti-Robbery Squad (SARS), a unit activists blamed for a campaign of extortion, violence, kidnapping and intimidation.

Activists say those government promises have proven hollow. SARS has largely been reconstituted under another name, and abuses are being perpetrated by other units with impunity.

"It is very disappointing," Akinwunmi said, adding: "There's no account on anything, any human life or property."

On Wednesday, Information Minister Lai Mohammed said government and police were taking steps - some not publicized - to address police brutality. These include establishing judicial panels and promises that states would indict police for crimes.

"We are committed to ensuring a comprehensive police reform," Mohammed said.

Rinu Oduala, who served on a panel investigating police brutality in Lagos, quit in February in frustration because the body was failing to tackle the problem.

"While these panels were sitting, there were ongoing cases of police violence," she said. "The government has turned a blind eye to it all."

Far from becoming a more open society, Nigeria has slipped two points, to 45 out of 100, on the Freedom House index of world freedom. The watchdog cited extrajudicial killings, torture, and other abuses by military and law-enforcement agencies. Human Rights Watch said hopes for accountability "remain inconclusive and bleak".

In June, Nigeria banned Twitter after it deleted tweets by President Muhammadu Buhari. Activists say that makes it harder to organise.

Still, Akinwunmi is hopeful that the anniversary of the protests can again unite the nation.

"We will be able to remember the time that there was a time like this that we had one goal, one voice," he said.

Reuters