Suspected Islamic militants have struck for a fourth time in three days in Nigeria, killing 20 people including a traditional ruler in attacks in the northeast, local government and security officials said Wednesday.
Meanwhile, the military said all but eight of more than 100 teenage students kidnapped on Tuesday are free.
The unprecedented string of attacks, which started with a massive explosion in the capital that killed at least 75 people, has many questioning the ability of Nigeria's military to contain the 5-year-old Islamic uprising. It has killed more than 1,500 people this year alone, compared to an estimated 3,600 between 2010 and 2013.
"Once again, the sophisticated methods of the bombers and insurgents, the audacity of their open attacks and the devastating stealth with which they operate ... calls into question the strategy of the Nigerian security forces and their commitment to the fight," The Guardian newspaper of Nigeria said in an editorial Wednesday.
"As Nigeria bleeds all over, a more heart-rending phenomenon is the politicization of the insurgency," the independent and authoritative newspaper said. "The ruling elite seems conscienceless enough to be exploiting the crisis, in symbols and in substance."
Just last week the emir of embattled Gwoza district had appealed to the government to "save our souls," saying his people are being attacked daily.
By Tuesday, one of his local monarchs was dead.
"They simply walked right into the palace of the monarch and shot him in his bedroom, and on their way out they also shot his guard before fleeing," said local politician Hyeldi Bwala.
Wednesday morning, gunmen attacked the village of Wala, in Gwoza district, and killed 18 people, according to a local government official and an intelligence agent. They both spoke on condition of anonymity because they are not authorized to speak to reporters.
The emir, Idrissa Timta, had indicated security forces were inadequate and said he might have to flee to neighbouring Cameroon "where we may perhaps get protection."
"We in Gwoza have suffered too many attacks, killings and destruction," he said. "Our people have been forced to flee, our markets no longer operate optimally, food items, goods and wares are no longer coming in ... We want action from government so that lives can be saved."
The attacks come after Monday's explosion just miles (kilometres) from Nigeria's seat of government, timed for the busy morning rush hour to ensure maximum casualties, and Tuesday's abduction of about 100 young women taking final exams at a school, also in Gwoza.
All but eight of the young women — they were aged between 16 and 18 — were free by Wednesday night, military spokesman Maj. Gen. Chris Olukolade said in a statement. He gave no details.