Explosion at police HQ in northeast Nigeria kills 4

Bombs retrieved from Boko Haram exploded accidentally today at police headquarters in Nigeria's northeastern city of Yola, killing four people and wounding a score of officers and school children cut by shattered glass, officials said.
Crying kids, screaming parents and panicked market vendors began running for their lives when an officer warned of the possibility of a secondary explosion in Yola's Jimeta neighborhood. The police station is in a commercial area surrounded by a market, the main prison, a post office, a TV station and two primary schools.
Fire engines and ambulances with sirens blaring arrived at the scene. The office of the Nigerian Police Anti-Bomb Squad was razed along with nearby buildings in the police complex.

The powerful blast shattered windows for blocks.
"The bombs (that exploded) are among those retrieved from Boko Haram," deputy superintendent Othman Abubakar told The Associated Press, denying suggestions they were planted.
Rescue officials recovered four bodies and ferried at least 20 wounded children and people to the hospital, according to PR Nigeria, an agency that disseminates government statements.
Boko Haram extremists have attacked the city many times. Suicide bombings in Yola in October at the main mosque and in November at a bustling truckers' station killed 64 people and wounded about 180.
Yola, capital of Adamawa state, is overrun by refugees among 2.5 million people driven from their homes by Boko Haram's 6-year-old Islamic uprising. It has killed some 20,000 people and spread across Nigeria's borders.