MAIDUGURI, Nigeria — Nigerian security forces dismissed reports on Wednesday that soldiers and police had shot dead at least 30 people in revenge for a bomb attack in the northeastern city of Maiduguri. Residents told Reuters Nigerian forces had opened fire on civilians and burned houses in the city – the headquarters of Islamist rebel group Boko Haram – after an explosion hit a military convoy there. Nurses in the Umaru Shehu hospital said they had seen 35 bodies, five in army uniform and the rest wearing civilian clothes, after the shooting on Monday. The military and police Joint Task Force (JTF) in northeastern Borno state dismissed the reports as a lie. “No civilian or terrorist was killed by the JTF troops,” task force spokesman Lt. Col. Sagir Musa said in a statement. There was “no established or recorded case of extra-judicial killing, torture, arson or arbitrary arrest by the JTF in Borno state,” he added. Musa said the houses had been burnt in the explosion that targeted the military convoy. Residents had told Reuters the buildings were set alight hours later. Nigerian forces have launched a crackdown on Boko Haram, an insurgent group that wants to carve an Islamic state out of northern Nigeria. Analysts say the military campaign has had some success - limiting Boko Haram's ability to carry out large scale attacks. But the army's heavy-handed tactics have angered some locals. “This is revenge mission. Why are they killing innocent people instead of fishing out the Boko Haram members?” said Aishatu Ibrahim, as she wept over the phone. Her husband, who had no link to the Islamists, was killed in the operation, she said. Boko Haram's fighters have killed more than 1,000 people in bomb or gun attacks since they intensified their struggle in 2010, rights groups say. Campaign groups have also accused the military of killing scores of civilians during raids. The United States has labelled three senior members ‘terrorists' and put them on its sanctions list. Eight militants over police killings Police in northern Nigeria said Wednesday they have arrested eight suspected Islamist militants over the killing of two police officers who were shot while guarding medical personnel. The officers were killed by motorcycle-riding gunmen on Tuesday while escorting a group going door-to-door around the city of Kano conducting polio vaccinations, police spokesman Magaji Majia said. Kano, Nigeria's second largest city, has repeatedly been targetted by Boko Haram Islamists, including several attacks on the security services, and Majia said the insurgents could be behind the latest violence. — Agencies