DAKAR, Senegal — Security officials in Nigeria failed to act after being alerted that Boko Haram militants were on their way to a town where they eventually kidnapped 110 schoolgirls, Amnesty International said on Tuesday, in findings that were swiftly denounced by the military.

The Nigerian Army and the police received at least five calls up to four hours before militants raided a boarding school in Dapchi last month, but they did not take measures to stop the abduction or to rescue the girls after they were gathered into vehicles and driven away, Amnesty said in a news release.

Military officials responded in forceful terms to Amnesty’s accusations, with a spokesman suggesting the group was being “economical with the truth” and trying to undermine “our military and our institutions.”

In a longer statement issued on Tuesday, the military went further in its criticism of the rights group. “Most of their narratives are outright falsehood and a calculated attempt to whip up sentiments and mislead unsuspecting Nigerians,” the statement said.