ABUJA, Nigeria (AP) — Nigerians on Friday marked three years since the mass abduction of nearly 300 schoolgirls by Boko Haram extremists amid anger that government efforts to negotiate their freedom appear to have stalled.

Activists were rallying in the capital, Abuja, and commercial hub Lagos to urge President Muhammadu Buhari’s government to do more to free the nearly 200 schoolgirls who remain captive.

“It is still a nightmare to me. It is still fresh as if it happened last night,” said Rebecca Samuel, whose daughter Sarah remains missing. “The government is trying, but I believe they can do more than what they are doing.”

After a few of the girls escaped on their own, Nigeria in October announced the release of 21 of the Chibok schoolgirls after negotiations with the extremist group. It said another group of 83 girls would be released “very soon.”

No one has been freed since then. The government this week said negotiations have “gone quite far” but face challenges. It refused to give details, citing security reasons. Buhari on Friday said Nigeria is “willing to bend over backwards” to secure the schoolgirls’ release.

“It is deeply shocking that three years after this deplorable and devastating act of violence, the majority of the girls remain missing,” a half-dozen independent experts for the United Nations, who visited Nigeria last year, said in a statement this week.

The failure of Nigeria’s former government to free the girls sparked a global Bring Back Our Girls movement and was a factor Buhari’s 2015 election win over former President Goodluck Jonathan.

The schoolgirls from Chibok village are among thousands of people abducted by the Nigeria-based Boko Haram as it continues to threaten parts of the northeast and has spread into neighbouring countries.

“I thank the Almighty for sparing the lives of some, and mine is among them,” said Esther Yakubu, who wept last year when she watched a Boko Haram video with the first proof of life of her daughter, Dorcas, since her capture. Her daughter has not yet been freed.

When marking the anniversary last year none of the schoolgirls had been freed, “but today we have 24 of them. That’s progress,” Yakubu said.

The Chibok abduction is not even the largest. Nigerian officials refuse to acknowledge the abduction of more than 500 children from the northeastern town of Damasak in November 2014, Human Rights Watch said last month. Nigerian officials have not responded to requests by The Associated Press for information.

Buhari late last year announced that Boko Haram had been “crushed,” but it continues to carry out deadly suicide bombings, often strapping them to young women. Children have been used to carry out 27 attacks in the first three months of this year, already nearing last year’s total of 30, the UN children’s agency said this week.

“Today, the group has been degraded and is no longer in a position to mount any serious, coordinated attack, other than sporadic suicide attacks on soft targets,” the president said Friday. “Even at that, their reach is very much confined to a small segment of the northeast.”

But on Wednesday, Nigerian security officials said they had thwarted plans by Islamic State group-linked Boko Haram members to attack the embassies of the United States and Britain, along with “other Western interests” in the capital. One faction of Boko Haram is allied with the Islamic State group.

Nigeria’s military in the past year has rescued thousands of Boko Haram captives while liberating towns and villages from the group’s control, but many have been detained as possible Boko Haram suspects.

Boko Haram’s seven-year Islamic uprising has killed more than 20,000 people and driven 2.6 million from their homes, with millions facing starvation because of the disruption in markets and agriculture.