BAGA, Nigeria (AP) ― Fighting between Nigeria’s military and Islamic extremists killed at least 185 people in a fishing community in the nation’s far northeast, officials said Sunday, an attack that saw insurgents fire rocket-propelled grenades and soldiers spray machine-gun fire into neighborhoods filled with civilians.

The fighting in Baga began Friday and lasted for hours, sending people fleeing into the arid scrublands surrounding the community on Lake Chad. By Sunday, when government officials finally felt safe enough to see the destruction, homes, businesses and vehicles were burned throughout the area.

The assault marks a significant escalation in the long-running insurgency Nigeria faces in its predominantly Muslim north, with Boko Haram extremists mounting a coordinated assault on soldiers using military-grade weaponry. The killings also mark one of the deadliest incidents ever involving Boko Haram.

Authorities had found and buried at least 185 bodies as of Sunday afternoon, said Lawan Kole, a local government official in Baga.

He spoke haltingly to Borno state Gov. Kashim Shettima in the Kanuri language of Nigeria’s northeast, surrounded by still-frightened villagers.

Officials could not offer a breakdown of civilian casualties versus those of soldiers and extremist fighters. Many of the bodies had been burned beyond recognition in fires that razed whole sections of the town, residents said. Those killed were buried as soon as possible, following local Muslim tradition.

Brig. Gen. Austin Edokpaye, also on the visit, did not dispute the casualty figures. Edokpaye said Boko Haram extremists used heavy machine guns and rocket-propelled grenades in the assault, which began after soldiers surrounded a mosque that they believed housed members of the radical Islamic extremist network Boko Haram. Extremists earlier had killed a military officer, the general said.

Edokpaye said extremists used civilians as human shields during the fighting _ implying that soldiers opened fire in neighborhoods where they knew civilians lived.

“When we reinforced and returned to the scene the terrorists came out with heavy firepower, including (rocket-propelled grenades), which usually has a conflagration effect,” the general said.

However, local residents who spoke to an Associated Press journalist who accompanied the state officials said soldiers purposefully set the fires during the attack. Violence by security forces in the northeast targeting civilians has been widely documented by journalists and human rights activists. A similar raid in Maiduguri, Borno state’s capital, in October after extremists killed a military officer saw soldiers kill at least 30 civilians and set fires across a neighborhood.

Sunday afternoon, the burned bodies of cattle and goats still filled the streets in Baga. Bullet holes marred burned buildings. Fearful residents of the town had begun packing to leave with their remaining family members before nightfall, despite Shettima trying to convince some to stay.

“Everyone has been in the bush since Friday night; we started returning back to town because the governor came to town today,” grocer Bashir Isa said. “To get food to eat in the town now is a problem because even the markets are burnt. We are still picking corpses of women and children in the bush and creeks.”

The Islamic insurgency in Nigeria grew out of a 2009 riot led by Boko Haram members in Maiduguri that ended in a military and police crackdown that killed some 700 people. The group’s leader died in police custody in an apparent execution. From 2010 on, Islamic extremists have engaged in hit-and-run shootings and suicide bombings, attacks that have killed at least 1,548 people before Friday’s attack, according to an AP count.

In January 2012, Boko Haram launched a coordinated attack in Kano, northern Nigeria’s largest city, that killed at least 185 people as well. However, casualty numbers remain murky in Nigeria, where security and government officials often downplay figures.

Boko Haram, which means “Western education is sacrilege” in the Hausa language of Nigeria’s north, has said it wants its imprisoned members freed and Nigeria to adopt strict Shariah law across the multiethnic nation of more than 160 million people. While the administration of President Goodluck Jonathan has started a committee to look at the idea of offering an amnesty deal to extremist fighters, Boko Haram’s leader Abubakar Shekau has dismissed the idea out of hand in messages.

The Boko Haram network, which analysts and diplomats say has loose links to two other al-Qaida-aligned groups in Africa, has splintered into other groups as well. Its command-and-control structure also remains unclear. Recent Internet videos featuring Shekau have shown him with fighters carrying military weapons he said were stolen during attacks on Nigeria’s military. Those weapons have included rocket-propelled grenades and other heavy weapons.

Fighters suspected to belong to Boko Haram also have been seen in northern Mali, where heavily armed Islamic extremists took power in the weeks following a military coup in that West African nation. Analysts also have worried that Boko Haram may get its hands on weapons smuggled out of Libya following its recent civil war.

Despite the deployment of more soldiers and police to northern Nigeria, the nation’s weak central government has been unable to stop the killings. Meanwhile, violent atrocities committed by security forces against the local civilian population only fuels rage in the region.