Hundreds of children and youths have been thrown out of school in Nigeria's northeast Borno State, as Boko Haram insurgents constantly attacked educational institutions and other public and private facilities in the area.

Though the extremist group's violent activities have spread to the two neighboring states of Adamawa and Yobe, Borno has been worst affected by the insurgency since it began three and a half years ago.

Boko Haram's attacks on schools and homes have also separated children from their families, denying them the needed parenting in their adolescence, said Abdulraman Mustapha, an analyst heading a peace advocacy group called Northern Youth for Grassroots Development.

"Education is key to development but the north is generally lagging behind in education when compared to other parts of the country," he said.

Now it is a common sight to see many children roaming the streets of Maiduguri, the state capital, said Andrew Tada, a technician, adding that the number of children separated from their families due to Boko Haram's attacks has swelled up the huge population of street urchins in Borno and Yobe.

One of such children, 15-year-old Bulama Bukar, was seen walking aimlessly on a rustic street in Maiduguri in a hot afternoon.

A dingy box hung precariously on his right arm. There were no books or writing materials in this 20-inch-long box as a close look later showed.

In the wooden box were disused rubber slippers, shoe polish and other locally-produced tools for mending shoes.

"Boko Haram sent me out of school," Bukar said as he wiped sweat from his rough face.

The temperature was about 43 degree Celsius and the boy looked worn out.

"I was in junior secondary school ... until July 2013 when Boko Haram attacked our town and burnt down our school," he said.

"It was in the evening and people in the town were saying Boko Haram threatened to revisit us again with more attacks. So, my parents and I fled. That was what brought me to Maiduguri," Bukar explained.

He said he preferred remaining in his village but Boko Haram's threat forced his parents to have a rethink.

"I came to Maiduguri with my parents. My parents are working somewhere else in the town and I'm also staying in another part of the city with a family friend but I have to take care of myself -- feeding and clothing," he said. "I'm missing school; this shoe-mending is not for children."

For Abram Dauda, a primary school pupil at Chikide in Gwoza area, probably nothing hurt him much as the end of his education as he said Boko Haram dashed his hope of becoming a scientist.

"They burnt down our school, killed many people, and my parents fled the village," he said.

The 11-year-old boy washes plates in a local restaurant in Maiduguri for two U.S. dollars a day, while his parents and siblings take refuge in neighboring Cameroon.

On April 14, armed Boko Haram men sneaked into the premises of the Government Girls Secondary School, Chibok, south of Borno and abducted 276 girls, spurring an international outrage.

Authorities said 53 of the kidnapped schoolgirls managed to escape from the abductors' camp and are now with their families.

The abduction came barely two months after Boko Haram slaughtered over 50 students of Federal Government College in nearby Buni Yadi, Yobe State.

Late 2013, the insurgents also shot dead 40 students of College of Agriculture in Gujba, about 20 km away from Buni Yadi.

Inuwa Kubo, Borno's state commissioner of education, said the state had rebuilt 215 classrooms out of a total of 800 classrooms burnt.

"I must confess these attacks on schools and educational facilities by Boko Haram have set us back. The tragedy is that as we're renovating schools, the insurgents are also burning more and even destroying those we just renovated," he said.

Kubo said that although the government paid a monthly allowance to parents, especially in the northern part of the state, to encourage them to send their children to school, Boko Haram attacks were still discouraging them.

According to Mala Daura, vice chancellor of the University of Maiduguri, the insurgency has reduced yearly admission applications from 7,000 to less than 3,000.

But Dauda Mbaya, a journalist, said Boko Haram's impact is not limited to the education of children alone.

For the children whose parents were killed by the insurgents or died in clashes between the group and government troops, Mbaya said, such a tragic fate may have caused some disorders in their lives.

The way forward, he said, is for the government to commence a total reorientation of youths in the affected northeast states and rebuild infrastructure.