Emergency services told the AFP news agency that the blast was caused by an improvised explosive device.
It occurred at the Malkohi camp for internally displaced persons (IDPs) on the outskirts of Yola in Adamawa state.
Yola has been seen as a relative safe place for those fleeing the violence.
The BBC's Chris Ewokor in Abuja says this is the first attack on a camp for IDPs in the north-east.
The explosion happened in a warehouse, emergency services say.
There are reportedly more than 1,000 children in the camp.
Two million people have been forced from their homes since the militants launched their insurgency in north-eastern Nigeria in 2009.
According to Amnesty International, at least 17,000 people have been killed in the conflict.
Although the militants have been forced out most of the territory they had seized, they are still active and there has been an upsurge in suicide attacks since President Muhammadu Buhari took office in May.
Teaching Boko Haram militants to play football
Who are Boko Haram?

Steyn left the pitch mid-over twice on day three and was taken for scans but they showed no sign of a muscle tear.
The world's top-ranked bowler had a morning fitness test at Kingsmead but again felt discomfort.
The 32-year-old will have more tests to see if he will be fit for the second Test, which starts on 2 January.
The doubts over Steyn's fitness added to the problems for South Africa, who trailed England by 261 runs before the fourth day of the series opener and were facing a struggle to save the game.
The right-arm bowler had only just returned to the Proteas side after missing the majority of their tour of India with a groin injury.
South Africa have also been disrupted by speculation about the future of star batsman AB de Villiers.
The 31-year-old, who is also keeping wicket during this Test, said on Monday that he was looking to ease his workload amid rumours he is considering retiring.
"There are a lot of rumours flying around I hear, but for the last two to three years the only talk I've been doing is to keep myself fresh and to have a bit of rest here and there," said De Villiers, who is ranked the number three Test batsman in the world.
"It's always been the most important thing for me to enjoy my cricket. It's just important to look at the schedule and for me maybe not to play all kinds of cricket.
"That's the only thing that I've been talking about. To keep myself fresh and to keep enjoying the game. I love representing my country and nothing has changed."

The 30-year-old won the last of his 34 caps against New Zealand in 2013.
"I had a phone call from Eddie before he picked the England squad saying I need to get back to the running rugby and get hands on the ball in the wide channels," said Foden.
"That's the first time anyone's ever told me that from England - it was always the other way around."
He added to BBC Radio Northampton: "They always said my counter game was good and I was good with ball in the wide channels but the rest of the game needed working on so it was quite bizarre for him to turn around and say that to me."
Saints, losing Premiership semi-finalists last season, have struggled for form this term and are currently seven points off fourth-placed Harlequins in sixth.
And Foden said his conversation with Jones was linked to the problems his club side have had.
"It just shows where we are as a Northampton back-line, we haven't been firing," he added.
"Individually, I haven't been getting the ball in the wide channels and doing what I used to do in a Northampton Saints shirt.
"Hopefully that will light a fire for a few of us - I think Luther [Burrell] had the same conversation as well."
At least three people have died when a bomb exploded at a camp in north-eastern Nigeria for people who have fled their homes because of the Boko Haram Islamist insurgency.
[NEXT_CONCEPT]
South Africa pace bowler Dale Steyn will not bowl again in the first Test against England because of a right shoulder spasm.
[NEXT_CONCEPT]
Northampton full-back Ben Foden says England head coach Eddie Jones has told him to "get back to running rugby".