Boko Haram attacked northeast Nigeria's largest city Sunday, killing more than 200 people and putting hundreds of thousands more "at grave risk" just as US Secretary of State John Kerry landed in the country.
The militants laid siege to Maiduguri — both the birthplace of Boko Haram and the city where many of its victims have sought refuge — as well as the nearby town of Monguno. The extremist group also blocked roads in the area to prevent civilians from fleeing.
Several villages to the south in Adamawa state also came under attack. The Associated Press cited reports from survivors there who said the militants slit the throats of residents, looted and burned homes, and abducted women and children.
"We believe hundreds of thousands of civilians are now at grave risk," Amnesty International told the AP.
Residents of Maiduguri, the capital of Borno state, told the BBC they awoke to gunshots and booming explosions. One female resident said "hundreds of thousands of people" were fleeing, and that civilian volunteers were fighting to defend the town since the military had proved inadequate.
"Only prayers will save us now, not the military," the woman said.
Nigeria's military tweeted that a curfew had been imposed on Maiduguri, and that the militants had begun "retreating."
Another resident confirmed to the BBC that all businesses were closed and no civilian vehicles were allowed on the roads.
"Everyone is at home, but there are the civilian vigilantes, the police and the military who are patrolling on the streets," he said.
More than 200 combatants were killed in the fighting, according to soldiers and civilian self-defense fighters who counted bodies and spoke to the AP on the condition of anonymity.
"We're still combing the bush for their corpses, we pursued the Boko Haram men until Auno, 12 km outside the city… some fled towards Mainok," a Civilian Joint Task Force leader told Reuters.
The fighting broke out just as Kerry was arriving in Lagos, the nation's commercial capital and largest city, to urge peace after the presidential election scheduled for next month. Kerry met Sunday with President Goodluck Jonathan, whose victory in 2011 prompted riots that killed hundreds of people. Kerry also met with the opposition candidate, Muhammadu Buhari, Nigeria's former military dictator.
Despite criticisms that the US has largely ignored violence in Nigeria — including a Boko Haram massacre that may have killed as many as 2,000 people in one week earlier this month — Kerry insisted that his nation is "deeply engaged."
Kerry noted that the US would continue sharing intelligence with Nigeria, a BBC correspondent tweeted Sunday.
Boko Haram's Sunday attacks were strategically designed to sabotage the upcoming elections, some analysts speculated.
The extremist Muslim group has led a six-year terror campaign that has included suicide bombings, kidnappings of children, and mass killings.
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