NEW DELHI/ISLAMABAD (Reuters) -A blast was heard in Pakistan's eastern city of Lahore on Thursday morning, according to broadcaster Geo TV and a Reuters witness, a day after Indian strikes at multiple locations in the country and fears of an escalation in conflict between the nuclear-armed neighbours.

Amid fears of further escalation, Pakistan said it shot down 12 drones overnight, while India said it targeted an air defense system in Lahore.

Video footage shows a bright flash from the residential Islamic seminary outside Bahawalpur in central Pakistan as India attacked its neighbor.