Officials in northwest Pakistan say 15 militants have been killed in a clash between rival militant Islamist groups.

Authorities say several people were wounded Saturday in the battle in the Orakzai tribal region near the Afghan border.

It was not immediately clear what caused the clash.

In the south, officials say a bomb partially exploded Saturday outside the Red Cross office in Karachi.

Authorities say two motorcyclists delivered the bomb to the site.

Officials say there were no injuries from the small blast.