The opposition lawyer has championed the popular protest that began Thursday. Some see a rule-of-law hero; others cite political expedience.
Gunmen abducted John Solecki, head of the UN refugee agency in Quetta, on his way to work Monday.
The attack highlights the need for alternative routes.
It targeted a camp of the group linked to the Mumbai attacks Sunday.
Barack Obama says resolving the Indian-Pakistani dispute over Kashmir will be a goal of his presidency, ending eight years of silence on the issue.
The government's disaster relief in Balochistan comes amid ongoing efforts to reach out to the troubled province.