Authorities believe the attack in the northern city of Kano was the work of Boko Haram militants, although the group did not immediately claim responsibility.
Many of the displaced ended up in camps in the city of Yola. Now they're racing further away as concerns grow that Yola also faces attack, and that the government isn't doing enough to stop it.
A day after reports that Boko Haram militants had captured the town where they abducted hundreds of schoolgirls in April, the government says it has regained control of the northeastern city.
The rebel group that abducted nearly 300 girls in April has captured the town where they were taken, dashing faint hopes that a cease-fire deal with the government could still be salvaged.
The Islamist extremists have seized a string of towns in the northeast, displacing hundreds of thousands and creating a humanitarian crisis. Monday's attack on a boys school killed up to 50 students.
The Nigerian extremist group says more than 200 girls it kidnapped from a school in April have been married to fighters. The group also denies stories that it has reached a cease fire deal.
The reported abductions continue to cast doubt on a truce announced by Nigerian officials. The deal was supposed to culminate in the release of 276 girls the group kidnapped in April.
A day after Nigeria's announcement last week that a truce had been signed and the release of more than 200 girls secured, 25 more were said to have been kidnapped by extremists.