leading fisherman and a resident said Thursday.
"On Monday around 4 pm (1500 GMT), Boko Haram attacked three villages on the shores of Lake Chad where they slaughtered 10 people, all of them fishermen," Abubakar Gamandi, head of the fisherman's union in Borno State, told AFP.
The account was confirmed by a local fisherman, Buhari Dan-Malam, who lives in Doron Baga.
"The Boko Haram gunmen came around 4:00 pm and they attacked three villages (that are five kilometres/three miles from Doron Baga). They slit the throats of 10 people," he said.
The villages attacked on Monday were Bundaram, where they killed four people, Fishdam, where they killed two people, and Kwatar Mali, where they killed four people," Gamandi said."Boko Haram decided not to use guns so as not to attract the attention of soldiers from Baga. This is why they used knives to slaughter their victims," he said.
The fishing villages around Baga were abandoned in January after some of the most deadly attacks by the Islamist sect.
But "in the last month, residents in the Baga area displaced by the Boko Haram takeover of the area in January have been returning to some villages secured by the military to continue their fishing business," Gamandi said.
"They take their catch back to Maiduguri (the state capital) to sell and make a living because living in the IDP (internally displaced people) camps has become difficult due to lack of food."
The army had authorised the displaced people to go back to fish in the villages, he added.
The jihadists had attempted to enter Doron Baga on Monday but villagers "mobilised and began booing them. And that helped in keeping them away," Dan-Malam said.
"Because of our daring act we let them believe soldiers were in the village. They then went and camped in Dawashi, another village. To avoid being attacked, we went to Maiduguri," he said.
But they later returned "because fishing is all we know. Now there is fish in the lake which had been left untapped since January," he said.
Last week, nine water melon growers were also killed in Dabar Wiya where they had returned to harvest their produce, said Gamandi who did not provide further details.
The hundreds of islets separated by channels hidden by tall grass in the Lake Chad region provides cover for the militants to steal livestock and food from local inhabitants.
The jihadists, now affiliated with the Islamic State group, have been using the islands as a rear base after being routed from their traditional strongholds in Nigeria by a four-country military offensive against them.
The Chadian army has launched a "major operation" to flush out Boko Haram jihadists from Lake Chad, sparking violent clashes on Monday between soldiers and the group.
Chadian forces have "around 1,000 men positioned to occupy all the islands and neutralise Boko Haram," a security official told AFP.