All schools have been asked to shut down and send children home because of security fears in Abuja, the capital city of Nigeria and nearby Nasarawa state.
Intelligence reports indicate armed groups plan attacks in many states, including the capital.
Schools, particularly in northern Nigeria, have become a significant target of kidnapping gangs during recent years, with several students being held for ransom.
President Muhammadu Buhari is presently meeting with security chiefs.
Most of the private schools were in the middle of exams when they suddenly had to close on Wednesday afternoon, July 27.
An official at the private school association owners in Abuja said that the order to shut down had come from local officials in the capital.
He said those schools with proper security arrangements would be allowed to hold a prize-giving ceremony for one day by the end of next week.
But the order has caused worries for parents in a city populated by several civil servants, who usually send their children to private schools.
While a few schools in Abuja had already shut down for the term, most were not scheduled to close till next week.
Residents of Abuja have been feeling worried since armed men broke in a prison in the city and freed hundreds of convicts a few weeks earlier.
On Sunday, around three soldiers from an elite unit of presidential guards were murdered in the Bwari district of the city.
They had been replying to warnings of a coming attack on the Nigerian Law School in the area. A nearby Veritas University has since closed down and sent students back home.
The very next day, the government closed one of its secondary schools in the Kwali suburb of Abuja after a nearby security incident.
On Wednesday, senators of the opposition gave the president a six-week ultimatum to resolve the security crisis or face impeachment, though they lack the numbers to do so.
