Abuja. A man claiming to be leader of the Nigerian Boko Haram insurgents, Abubakar Shekau, on Wednesday vowed more attacks in the northern parts of the country until it installs and decrees strict sharia law in the country.Shekau, reported to have been killed by the Nigerian military, said in a video released on Wednesday in the northeast city of Maiduguri, that he will stop democracy in the Africa’s most populous nation.  "I swear by Allah that there will be no democracy in Nigeria. We are going to rise against it and we shall soon defeat. The concept of government of the people by the people, for the people cannot continue to exist. It shall soon, very soon, be replaced by ‘Government of Allah, by Allah for Allah,” Shekau boasted.He was surrounded by dozens of his lieutenants with guns who punctuated his speech with laughter and occasional banters against the Nigeria military.He also denied the claim that he died at a Nigerian border where he was ferried by his aides to receive treatment."The world should know that I can not die except by the will of Allah. I have told you that all that I do is prescribed by the Quran. The essence of it is to carry out the injunctions. Don’t bother yourselves stopping me because I cannot be stopped. The war is more grievous than you think, and it will consume you,” he added. He claimed the sect was responsible for the attack last Tuesday on unarmed civilians at Benisheik, about 50 km to Maiduguri, Borno State capital and former stronghold of the insurgents. He said the sect has succeeded in attacking Monguno, where a military barrack is located, Benisheik and other towns around Maiduguri.Lt.-Col. Sagir Musa, spokesperson of the military-led Joint Task Force (JTF) had said in a statement that the head of the Boko Haram sect, Shekau, may had been killed in a gun battle with Nigerian security forces in the northeast Borno State.