Children displaced by Boko Haram attend school in Maiduguri, Nigeria, on Dec. 7, 2015. (Sunday Alamba/AP)

This story has been updated.

It has been more than three years since Nigeria's government declared victory over Boko Haram, the Islamist militant group, but that assertion has been put to the test several times in the past few months.

In November, Boko Haram militants carried out bombings in Nigeria that killed dozens of people. The next month, the group attacked a Nigerian army convoy accompanying World Food Program trucks, killing four people. Then, last week, Boko Haram staged an attack on a boarding school for girls, one that echoed the 2014 kidnapping of 276 schoolgirls in the town of Chibok.

On Monday, the Government Girls Science and Technical School in Dapchi, a village in northeastern Nigeria, was attacked. NPR quoted witnesses as saying that 12 trucks carrying insurgents and mounted machine guns drove onto the school campus. As the militants approached and set off explosives, dozens of students and teachers fled into the surrounding bush, helping one another scale the compound fence.

Police said initially that the militants had come to raid the school's food supplies and that the girls had not been targeted. But when the attack ended, several girls were missing. School officials suggested at first that many of the local students had simply returned to their families on foot. Nigerian authorities claimed that no girls were abducted and that at least 76 were rescued. (Two bodies also were discovered.)

But by Wednesday, witnesses reported that at least some girls were taken away in trucks. And this weekend, Nigerian officials finally confirmed parents' worst fears: that 110 girls are still unaccounted for.

The government's confused response has left parents frantic. They said it echoed Nigeria's botched response to the Chibok kidnappings, when 276 girls were forced onto trucks at their boarding school and driven into the forest. Researchers and reporters found that local officials had been warned about the attack hours earlier but had failed to send in military reinforcements. Then-President Goodluck Jonathan waited two weeks before addressing the attack and refused international help.

About 60 girls escaped soon after the incident, and an additional 82 were later released in exchange for five Boko Haram commanders. But about 100 others remain in captivity. Just last month, the Islamist group released a video purporting to show some of the Chibok girls in captivity. Their faces were covered, and they said on camera that they did not want to return home.

Meanwhile, the nearly decade-long war against Boko Haram continues. While the government declared the group “technically defeated” in late 2015 after retaking much of the territory it once controlled, the insurgents' attacks haven't stopped.

As Siobhan O'Grady wrote for the Los Angeles Times, it will take more than money and military might to defeat Boko Haram. “It isn't just a matter of coming in with a stronger military presence,” Joe Siegle, director of research at the Africa Center for Strategic Studies, told O'Grady. “What the government needs to be doing now is winning the trust of the local population. ...  That's the real battle, the next chapter here. … That's where they've failed.”

Incidents like the school attack last week make that goal even harder to achieve.

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