Blast hits school bus in Pakistan-police

A senior local police superintendent said two children were wounded and the bus driver was killed. Another police official in a police control room also said two children were wounded.

Pakistan's government, which Washington sees as a ally in its war against militancy, faces a growing threat from what officials and analysts call a growing nexus of militant groups.

It's a murky mix that includes al Qaeda, Pakistani Taliban militants and other groups. Some are anti-Western while others are driven mostly by sectarian hatred.

Pakistani authorities are on alert for sectarian violence during Moharram, the holiest month for Shi'ite Muslims, which is currently underway. Sunni militant groups often attack Shi'ite gatherings during this period.

(Reporting by Kamran Haider and Zeeshan Haider; Writing by Michael Georgy; Editing by Chris Allbritton)