Maiduguri would be a major prize for Boko Haram
African states ought to act rapidly and by and large to control the developing danger postured by Nigeria's aggressor Islamists, the African Union boss has said.
Cross-fringe assaults into Cameroon demonstrated the dangers the Boko Haram gathering postured, Nkosazana Dlamini-Zuma said.
Nigeria has rejected AU or UN intercession, saying local armed forces are fit for managing the danger.
Its troops repulsed another assault by Boko Haram on the key north-eastern city of Maiduguri on Sunday night.
Boko Haram propelled a full-scale revolt in north-eastern Nigeria in 2009 to make an Islamic state.
The military was out in force in Maiduguri during President Goodluck Jonathan's visit on Saturday
In an address to African foreign ministers at the AU
headquarters in the Ethiopian capital Addis Ababa, Ms Dlamini-Zuma said
recent attacks by Boko Haram were deeply horrifying.
AU heads of state had agreed to include the conflict on the agenda of their summit, due to begin on Friday, she said.
Correspondents say Boko Haram and Somalia's militant Islamist
group al-Shabab will now dominate the summit, which was supposed to
focus on women's empowerment and development.
US Secretary of State John Kerry arrived in Nigeria on Sunday to call for peaceful elections next month.
Boko Haram seized the north-eastern Nigerian town of Monguno
on Sunday, raising further doubts about whether elections could be held
across the country on 14 February.
It controls many towns and villages in the north-eastern
Borno state and Maiduguri, the state capital, is seen as a prized scalp
for the group.
The conflict has caused a humanitarian crisis affecting some three million people, Nigerian officials say.
Tomi Oladipo, BBC Africa security correspondent
Capturing Maiduguri would be Boko Haram's most significant
achievement yet, taking the largest city in north-east Nigeria and
returning to the place where it began a full-scale insurrection in 2009.
It is also a battle the Nigerian military cannot afford to
lose. Boko Haram has been inching across Borno state and even if its
fighters are repelled now, another audacious attack is inevitable,
considering much of the area around Maiduguri is already under its
control.
The army has been working to defend its major cities from
Boko Haram raids but Nigerians would expect their soldiers to also be
reclaiming the towns seized by the insurgents, which we have not really
seen so far
In an interview with the BBC Hausa service, Borno state governor Kashim Shettima called on people not to panic.
"This is our land. No fear, no flight, no retreat. We should
not flee. We have a history dating back 1,000 years and I swear by
Allah we are going to beat [Boko Haram]," he said.
Thousands of people from areas seized by Boko Haram are taking refuge in Maiduguri
Chad has deployed troops to Cameroon to fight Boko Haram
A 24-hour curfew imposed on Sunday in Maiduguri has been relaxed and some businesses reopened on Monday.
Government troops beat back Boko Haram fighters who had
launched an assault on the city on Sunday night - the second in less
than 24 hours, an army source told the BBC.
Both attacks were in the Jimtilo district.
Loud explosions were heard in the city, a resident told the BBC Hausa service.
'Houses on fire'
A medical source said the four biggest hospitals in Maiduguri were overwhelmed with casualties.
Some relatives took away corpses that lay at the entrance of the Maiduguri General Hospital, he told the BBC.
Children as young as four years were among those who had been treated for bullet wounds, he added.
Boko Haram at a glance
- Founded in 2002, initially focused on opposing Western-style
education - Boko Haram means "Western education is forbidden" in the
Hausa language
- Launched military operations in 2009 to create Islamic state
- Thousands killed, mostly in north-eastern Nigeria - has also attacked police and UN headquarters in capital, Abuja
- Has abducted hundreds, including at least 200 schoolgirls
- Controls several north-eastern towns
- Has launched attacks on Cameroon
Why is Boko Haram so strong?
City under siege
Soldiers without weapons
Who are Boko Haram?
President Goodluck Jonathan visited Maiduguri on Saturday as part of his election campaign, his second visit in two weeks.
The army in Monguno, 140km (85 miles) north of Maiduguri, was
reported to have been overwhelmed when Boko Haram attacked on Sunday,
setting houses on fire.
A journalist in Maiduguri told the BBC that fleeing soldiers from Monguno had arrived at the barracks in Maiduguri.
Mr Kerry urged Mr Jonathan and the main opposition's
presidential candidate, former military ruler Muhammadu Buhari, not to
condone violence during what is expected to be a tense election
campaign.
He said the US could do more to help against Boko Haram, as long as the elections passed off smoothly.
Mr Kerry (centre) held talks with President Jonathan (right) during a rare visit to Nigeria
The US does not currently sell weapons to Nigeria's military because of its human rights record.
Last week, Nigeria's national security adviser Sambo Dasuki
told the BBC that regional armies were in "good shape" to take on Boko
Haram and so they did not need help from the UN or AU.
However, there have been many reports of government forces fleeing when Boko Haram fighters advance.
Some soldiers say they do not have enough weapons and working equipment to defend territory.
Chad, seen as having the most capable military in the region,
sent a convoy of troops and 400 military vehicles to Cameroon earlier
this month to battle Boko Haram.