ISLAMABAD, April 13 (Xinhua) -- A second bomb blast took place on Tuesday evening in the Pakistani capital Islamabad, but no casualties have been reported so far, police said.

The blast happened at a girls' college in G-10 sector of Islamabad, damaging a building as the windows have been shattered.

Police said the nature of the explosion is under investigation.

Earlier in the day, a bomb that was planted in a dustbin went off outside a boys' school in H-8 sector of Islamabad, injuring no one.