Police killed in Pakistan blast

Five police and two civilians have been killed in a suspected suicide attack in north-west Pakistan, police say.

Local government officials said the attack happened outside a college in the town of Dera Ismail Khan where paramilitary troops had been stationed.

At least 25 others were wounded in the blast, in which police were targeted as they investigated a minor explosion.

Dera Ismail Khan is close to Pakistan's restive tribal areas and has in the past seen sectarian violence.

It has witnessed strife between Pakistan's majority Sunnis and minority Shias.

Hundreds of people have been killed in a wave of suicide and other attacks over the past 18 months.