45 Killed as Gunmen Attack Karachi Bus

Security officials cordon off an area where gunmen attacked passengers on a bus in Karachi, May 13, 2015.

Women mourn as they visit a local hospital following an attack on a bus in Karachi, May 13, 2015.

A hospital official wearing a bloodstained shirt stands outside the hospital where the victims of a shooting attack were transported, in Karachi, May 13, 2015.

Crowds gather outside a hospital after an attack on a bus in Karachi, May 13, 2015.

Pakistani paramilitary troops stand guard outside a local hospital following an attack on a bus in Karachi, May 13, 2015.

A paramilitary soldier stands guard outside the hospital after an attack on a bus in Karachi, May 13, 2015.