A fresh wave of violence has left four persons dead and two others injured after suspected gunmen opened fire on beer parlours in Adamawa and Gombe States in Nigeria. Agency reports said both attacks which occurred Friday night in Yola and Gombe were similar as armed gunmen pulled up to separate beer parlours and opened fire on patrons. Adamawa State police commissioner, Ade Shinaba, said Saturday that one attack occurred Friday night at the Wuro-Hausa area of Yola, where two customers of a beer parlour were killed and one police officer injured. Police Public Relations Officer in the State, ASP Altine Daniel, said a policeman in mufti who was not on duty was also injured in the attack which occurred at about 9.00pm on Friday. She also confirmed that normalcy had returned to Guyuk, Lamurde, Numan and Girei Local Government Area of the state where there was an outbreak of sectarian crisis, which led to the imposition of a 24-hour curfew, which, she said, has now been relaxed to 12 hours by the State government. Suspected gunmen have killed more than 20 people in five different attacks in Yola and Mubi alone in the last 10 days, with the State government promising a reward of N25 million to anyone who could provide useful information that could lead to the arrest of the gunmen. The other shooting in Gombe left two persons dead and one other injured. Gombe State Police Command confirmed the attack on the beer parlour in Gombe metropolis Friday night. Police public relations Officer in the State, ASP Ahmed Mohammed, said the remains of the victims had been deposited at the State Specialist Hospital, Gombe. He said the police were already investigating the attack, but no arrest had yet been made. The latest attack, however, is suspected to be the handiwork of the Boko Haram sect. The suspicions follow the group’s earlier promise of more attacks. Already, the group has claimed responsibility for several attacks that have left scores of Nigerians dead. The most recent one was a Christmas Day bombing of a church in Madalla near Abuja that killed more than 30 persons. It was followed by a warning that Christians should leave the north due to the group’s desire for wider implementation of Sharia law across the country. U.N. Human Rights chief, Navi Pillay, on Thursday called on Nigerian political and religious leaders to conduct joint efforts to halt sectarian violence in the country. Pillay said it was especially important for Muslim and Christian leaders to "condemn all violence," including retaliatory attacks, stressing that those efforts could help stop a dangerous situation from "spiraling out of control. President Goodluck Jonathan had declared a state of emergency in some North-eastern states and followed this up with the deployment of extra troops in the north, but the attacks have continued unabated.