N'GOUBOUA, Chad (AP) — The Boko Haram militants attacked N'gouboua before dawn, marking the first time the Nigerian extremist group had hit a town inside Chad. Crying "Allahu akbar" or God is Great into the pre-dawn darkness, they opened fire indiscriminately and burned scores of mud-brick houses with gasoline, killing at least eight civilians and two security officers.

Nearly six years into its insurgency in Nigeria, the Islamic extremist group is now attacking villages in the other countries bordering Lake Chad — Chad, Niger and Cameroon — and local officials say the motive is greed, not a drive to establish an Islamic caliphate.

Some 3,400 Nigerian refugees had been living in N'gouboua at the time of the Feb. 13 attack and all have since been relocated further inland to a camp jointly run by the U.N. and the government of Chad, a predominantly Muslim country. Journalists who visited N'gouboua on Thursday saw traumatized and scared residents and nearly a dozen destroyed vehicles and motorcycles in the sand-blanketed streets.

The extremists had also set the town's sole mosque ablaze.

Adam Dogo, a town resident, pointed to the charred woven mats that once formed the mosque's ceiling. The call to prayer is muted now that the mosque's speaker has gone up in flames. The floor where men once prayed is covered in ash.

"What kind of Muslim sets a mosque on fire?" he asked. "The Boko Haram are against Islam."

During the attack, Dogo's son, Ndingou, fled into a house to hide along with several other children. Boko Haram militants torched their hiding spot and it wasn't long before one of the girls burned to death beside him. Ndingou was afraid of dying or being kidnapped by Boko Haram.

"I saw her body and I thought there was no way out," he recalled, his ears and the soles of feet badly burned. "I thought it was the end and I was going to die, but if they took me with them I would die too."

Chadian troops have stepped up their patrols though this lakeside community remains vulnerable to further attacks by militants in motorboats.

Only the day before, there was another attack on a village just 15 kilometers (nine miles) away. More than 200 Boko Haram militants ultimately were repelled by Chadian forces there, said local police commissioner Idriss Ibrahim. The heavily armed militants arrived in four boats with weapons including AK-47s and rocket-propelled grenades he suspects were stolen from the Nigerian military.

Some of the militants are now believed to be based on a Nigerian island in the lake though have used several other mostly abandoned islands on the Chadian side to launch their assaults. Authorities suspect some Chadians are giving them information since the highest-ranking local official was among those killed in N'gouboua.

"They clearly knew how to enter the village, where the army was based," said Dimouya Souapebe, the chief civil servant in Baga Sola region of Chad. "They knew where to attack, where to hit."

Some suspected collaborators already have been rounded up by the local authorities, and police are asking people to report suspicious strangers on the Chadian side.

While Boko Haram's leaders says it is attacking Chad and other neighboring countries because they support a regional military effort against the group, local authorities believe the group is motivated by greed. As northeastern Nigeria — where Boko Haram has traditionally been based — becomes increasingly isolated, the fighters are pillaging wherever they go.

"They don't have gas for their boats or medicine so they terrorize people so that they flee and they can take their things," Souapebe says.

Piles of burned fabric, tea pots and other destroyed household goods litter the sandy yard in front of El-hadji Mbodou Zezerti's home. The 78-year-old fled N'gouboua when he heard the pre-dawn gunfire. His wife and four of his children made it to safety, though 10-year-old Falmata was missing. When the family finally returned to the village two weeks later, they found her charred body inside their home.

Abakar Adoum, 34, lost his oldest brother that day, his throat slit when he encountered the militants while trying to flee. The children aren't sleeping, and there is little to eat in town.

"Our wives are afraid to sleep at night," he said. "I never thought Boko Haram would come here, and now we are afraid that they will come back. They must be eliminated."