Lagos - Nigeria's army on Monday said it had foiled a planned Boko Haram attack on the northeastern city of Maiduguri using powerful assault rifles and home-made bombs.Army spokesperson Colonel Sani Usman said in a statement that "nine terrorists sneaked into Maiduguri armed with AK-47 assault rifles and [a] Hilux vehicle laden with 20 improvised explosive devices". The IEDs were "meant to be detonated at some selected targets in the city", he added.Maiduguri, the capital of Borno state, was where Boko Haram was founded in 2002 and has been repeatedly targeted during the Islamist militants' bloody, six-year insurgency. At least 265 people have been killed in a wave of suicide and bomb attacks in the city since President Muhammadu Buhari came to power on May 29, vowing the crush the militants. On September 20, at least 117 were killed in a single attack.Usman did not elaborate in the statement about potential targets and refused to comment further when contacted by AFP to ask whether the nine had been arrested. But he added: "We will let you know at the conclusion [of a preliminary investigation] what exactly they wanted to do." Boko Haram, which is allied to ISIS in Syria and Iraq, wants to create a hardline Islamic state in northeast Nigeria.At least 17 000 people have been killed since 2009 and 2.6 million forced from them homes in violence that has increasingly hit Nigeria's neighbours Cameroon, Chad and Niger. Nigeria's army has in recent months claimed a series of successes against Boko Haram, pushing them out of captured territory, destroying camps and rescuing hundreds of people held captive. It has also claimed the arrest of a number of wanted suspects. On Monday, the army said it had "discovered and destroyed" an IED and rocket-making factory near the town of Bama, 72km southeast of Maiduguri by road. Items recovered included gas cylinders, pipes, poles and welding equipment plus locally made rocket shells, unprimed IEDs and chemicals.