Lagos - A daring Boko Haram raid in the north Nigerian city of Maiduguri was an embarrassing setback for the security forces, further eroding claims the Islamists have been significantly weakened, analysts said on Tuesday.
But experts also argued that a six-month-old offensive against the militants has made some gains and that sustaining pressure was the best option, with prospects for peace as bleak as ever.
The early morning attack on Monday, reportedly carried out by hundreds of heavily armed militants, targeted air force and army positions, despite the military saying the city had been largely secured.
Nnamdi Obasi, Nigeria researcher for the International Crisis Group, said the military can justifiably claim to have made Maiduguri safer in recent months "but clearly the events of yesterday showed that was not a permanent gain".
Boko Haram "is a very resilient group", he told AFP and labelled as "short-sighted" the notion that the insurgents had been confined to remote areas.
The latest violence forced authorities to close Maiduguri's civilian airport and impose a total ban on movements except for emergency personnel.
The rebels destroyed military aircraft, razed buildings and set shops and petrol stations ablaze, according to residents, who reported at least two civilian deaths, although the toll may have been much higher.
The military's disputed account said that gun battles following the initial attack left 24 insurgents and two service personnel wounded.
Kyari Mohammed, a Boko Haram specialist at the Modibbo Adama University in Yola, Adamawa state, said the attack showed the military "are not in control".
"That is the message (Boko Haram) are sending," he added, while Obasi said the military had been "caught off guard", noting that Boko Haram has a track record of exploiting such complacency.
More pressure needed
The state of emergency imposed in northeast Nigeria in May has been extended for six more months, giving the military more time to target the radical group, which has been blamed for killing thousands since 2009.
Some observers have questioned the effectiveness of the campaign, as hundreds of civilians, including scores of students, have been killed.
But despite doubts about the campaign's effectiveness, "in the short-term, clearly the operation has to be sustained" and units in the region may need to be better resourced, said Obasi.
Boko Haram is widely seen as a fractured group and there had been hope that some camps could be open to negotiations but a recent bid to kickstart amnesty talks with some insurgent leaders achieved nothing.
The opportunity for any further dialogue is currently "very slim", Obasi assessed.
Inside Maiduguri, academic and commentator Mallam Kabir demanded the security forces do more.
"What happened in Maiduguri on Monday is a clear indication that Nigerian authorities are not serious about the terrible security situation," said the University of Maiduguri lecturer.
Mohammed agreed that the military needed to maintain the pressure but said the government must do "whatever it takes" to open a line of dialogue, in part because recent history has proven that force alone cannot stop the violence.
Citing security sources, Obasi said the Maiduguri attack reinforced the need for a regional strategy against the rebels, with Cameroon, Chad and Niger helping to seal borders and contain cross-border weapons flow.
Nigeria has voiced concern that Boko Haram fighters often avoid pursuit by fleeing into a neighbouring state and the group acquires most of its weapons from outside Nigeria.
While experts have agreed that Nigeria needs outside help, few expect it will be forthcoming.
For Obasi, if Nigeria actually wants help from its neighbours they will "have to pay for it themselves" -- and should plan to do so.
Landlocked Niger and Chad are among the world's poorest countries with their own domestic security challenges, while Cameroon has shown little interest in committing to an anti-Boko Haram strategy.
Nigeria is Africa's most populous country and top oil producer, with the continent's second-largest economy.
Boko Haram says it wants to create an Islamic state in the mainly Muslim north, which is poorer than the mostly Christian south.