Chad's military is facing accusations of killing "scores" of fishermen in Nigeria while conducting operations against jihadists, just days after a Boko Haram attack resulted in the deaths of around 40 people at a military base in Chad, according to fishermen and anti-jihadist militia reports to AFP on Thursday.

The recent violence follows a Boko Haram assault on the Chadian army that claimed approximately 40 lives near the Nigerian border, as confirmed by government and local sources on Monday. A local source reported that "a garrison housing more than 200 soldiers was targeted by Boko Haram" late Sunday.

The presidency issued a statement indicating that the attack occurred near Ngouboua in western Chad and "tragically left about 40 dead." In response, Chadian President Mahamat Idriss Deby Itno visited the site on Monday and initiated an operation "to pursue the attackers and track them down to their farthest hideouts," according to the statement.

Local sources reported that Boko Haram militants took control of the garrison, seized weapons, and set fire to vehicles equipped with heavy arms before retreating. In retaliation, the Chadian army launched airstrikes on Wednesday, targeting Tilma Island in the Kukawa district on the Nigerian side of Lake Chad, where fishermen were working.

Two anti-jihadist militia members assisting Nigerian forces against militants claimed that "scores" were killed in the airstrike. Babakura Kolo, a militia leader, stated, "There was an attack on fishermen by a fighter jet belonging to the Chadian military in Tilma Island, which killed scores of fishermen." He added that the jet mistakenly identified the fishermen as Boko Haram terrorists responsible for the recent attack on the military base in Chad.

A Chadian general staff officer, who requested anonymity, explained to AFP that "Boko Haram fighters often blend in with the fishermen and farmers whenever they commit their crimes, making it difficult to distinguish between the population and the terrorists."

Most of the fishermen affected by the airstrike were from the towns of Baga, Doron-Baga, and Duguri along Lake Chad, according to Ibrahim Liman, another anti-jihadist militia member. Fisherman Sallau Arzika, who survived the airstrike, described how the fighter jet circled Tilma before dropping bombs as people ran for cover. "A large number of fishermen were killed. No one can give an exact number because bodies are still scattered across Tilma," he reported.

Some bodies and injured individuals were taken to a military base in Mile 4, near Baga, Arzika added. Labo Sani, a fisherman from Doron-Baga, recounted that two of his friends were killed in the airstrike, while another sustained serious injuries. "We were engaged in fishing, and it never crossed our minds that we would be attacked and killed by a fighter jet," Sani said.