A military court in Cameroon has handed down prison sentences of up to 20 years to 14 Boko Haram members, the country's state broadcaster Crtv reported Friday.

The defendants, who were arrested in March after the discovery of a weapons cache, admitted to being part of the Nigerian extremist group at a "public hearing" in the northern town of Maroua, said the report.

A suspected crossborder raid overnight by Nigeria's radical Islamic group Boko Haram killed two Cameroonian soldiers, a Cameroonian security official said Friday on condition of anonymity.

The attack occurred late Thursday in the border village of Balgaram in northern Cameroon. Eight soldiers posted there fought back, and "in the clash we lost two men," the official said.

At least one person was killed and eight other people injured when a blast ripped through a crowded bus station in Kano, northern Nigeria, police and witnesses said on Thursday.

The explosion happened at about 3:00pm (1400 GMT) at the New Motor Park in the predominantly Christian Sabon Gari neighborhood, which has previously been targeted by Boko Haram militants.

The United States on Wednesday called for a full investigation of twin bombings in Nigeria, denouncing the latest violence blamed on Boko Haram militants, which left at least 42 dead.

Two bombings in a key Nigerian city targeting a prominent cleric and a former head-of-state killed at least 42 people on Wednesday, in the latest violence blamed on Boko Haram Islamists.

Officials ordered everyone off the streets and imposed an around-the-clock curfew to restore order in the targeted city of Kaduna, as rescue workers raced to care for the dozens of wounded.

Relatives scarred by Boko Haram's mass abduction of Nigerian schoolgirls recounted their nightmare to President Goodluck Jonathan on Tuesday, in their first meeting with Nigeria's leader 100 days after the shocking attack.

Jonathan, whose handling of the hostage crisis has been fiercely criticized, held talks in the capital Abuja with the families of the teenagers who are still missing as well as girls who escaped their Islamist captors.

Relatives of the Nigerian schoolgirls kidnapped by Boko Haram 100 days ago met with President Goodluck Jonathan on Tuesday for the first time since the girls were seized.

The much anticipated meeting comes amid reports of a worsening security crisis in the northeast, where Islamists have occupied the town of Damboa and surrounding areas, with the military so far unable to chase them out.

Aisha Abubakar was at home two years ago when Boko Haram Islamists stormed through the door. She watched as they executed her father.

Children in Nigeria's deeply impoverished north face immense challenges in accessing education, and for the fatherless like 13-year-old Aisha the obstacles are even tougher.  

In the villages that line the border with Nigeria, even those charged with protecting Cameroonians from Boko Haram fighters fear the fall of darkness. 

A Nigerian helicopter crashed on Monday in an area where the military is battling Boko Haram Islamists, but there were no indications that it was shot down, a statement said.

"A Nigerian Air Force Mi-35 helicopter on a training mission this afternoon, crashed due to technical fault at a location south of Bama," in northeastern Borno state, defense spokesman Chris Olukolade said in a statement.