Leaders of three West African nations will meet in Chad on Thursday to discuss how to tackle a recent increase in activity by Boko Haram jihadist fighters in the region, the Chadian presidency told AFP.Nigerian President Muhammadu Buhari and Niger's Mahamadou Issoufou will meet behind closed doors with their Chadian counterpart Idriss Deby for a "mini summit" after which a statement will be issued.The armies of the three countries, along with Cameroon's, are operating in the Lake Chad region in the Multinational Joint Task Force ( MNJTF) to counter the Islamic State-affiliated Boko Haram, More than 27 000 people have died since the start of the Boko Haram insurgency, which began in Nigeria's remote northeast in 2009. Some 1.8 million people are still homeless after fleeing the violence."The increase in activities by Boko Haram elements in Nigeria and Niger in recent days is a concern for the heads of state who must decide on a rigorous plan of action," a Chadian diplomatic source said.Since July there have been at least 17 attacks against military bases. almost all of them in the region around Lake Chad, according to an AFP count.Last week militants raided a base in Nigerian village of Metele, near the border with Niger, leaving at least 44 soldiers dead, although troops who survived put the death toll at more than 100.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.