Chadian President Idriss Deby on Wednesday vowed to “wipe out” Boko Haram and called on the group’s chief Abubakar Shekau to give himself up, warning that he knew where the militant leader was hiding.

“It is in Abubakar Shekau’s interest to surrender, we know where he is. If he refuses to give himself up, he will suffer the same fate as his comrades,” Deby said at a press conference with his visiting Niger counterpart.

Deby said Shekau had fled the strategic northeast Nigerian town of Dikwa after Boko Haram fighters were chased out of the town by Chadian troops in fierce clashes last month.

The Chadian army at the time said two of its soldiers and 117 Boko Haram Islamists were killed in the fighting around Dikwa in Nigeria’s Borno state on February 17.

“We are going to win the war and we are going to wipe out Boko Haram, contrary to what certain media think. The Chadian and Niger forces will continue their mission to finally put an end to this shadowy group,” Deby said.

Little is known of Shekau, who has been declared a global terrorist by the United States and sanctioned by the United Nations.

– Enigmatic figure –

Nigerian security officials insist he is in fact a composite character whose role is taken by a rotating cast of different militant fighters.

According to security services, the original Abubakar Shekau was the son of poor farmers who was radicalised while attending theological schools and took over Boko Haram in 2010.

The Nigerian military said last September that a man posing as Shekau in videos posted online had in fact been killed after fighting with troops in the far northeast.

The United States and other experts, however, have questioned the credibility of that claim while Shekau has outright rejected it in a video.

Nigeria and its neighbours Chad, Niger and Cameroon last month launched an unprecedented joint campaign against the Nigeria-based Boko Haram group, after the militants widened their offensive with attacks in the neighbouring countries.

Nigerian military spokesman, Major General Chris Olukolade on Wednesday also pledged to snuff out Boko Haram, which claims to be fighting ot create an Islamic state in Nigeria.

“Indeed there is no going back or slowing down anywhere,” he old a news conference in the Nigerian capital Abuja.

“The air campaigns are continuing with a view to dislodging all the identified terrorist cells, enclaves or hideouts anywhere in the designated mission area,” the spokesman said.

“The continuous aerial bombardment of identified terrorists’ cells and hideouts by the Nigerian Air Force and subsequent ground offensive by the Nigerian troops pursuing the dislodged terrorists is proving worthwhile.”

The Boko Haram conflict has killed more than 13,000 people since 2009 and forced more than one million to flee their homes in northeast Nigeria.

On Tuesday, the Nigerian military claimed to have killed more than 70 Boko Haram fighters and repulsed their bid to seize a key town in Nigeria’s restive north.

Around 150 Boko Haram fighters entered the fishing town of Konduga on Monday with a large herd of cattle pretending to be ‎herders and opened fire on troops stationed in the town, leading to a six-hour gun battle.

Soldiers and vigilantes have repelled more than a dozen attacks by Boko Haram on Konduga, which is some 35 kilometres (21 miles) southeast of Maiduguri, the capital of Borno state and the birthplace of the Boko Haram movement.

Konduga could serve as a launching pad for attacks on Maiduguri.

The Boko Haram unrest has seen nearly 250,000 people flee to neighbouring countries, according to the United Nations refugee agency UNHCR.