KARACHI (AP)

A militant rammed an explosives-laden vehicle into the provincial headquarters of the paramilitary Pakistan Rangers in Karachi on Saturday, triggering an intense exchange of gunfire with security forces, police and witnesses said.

Ambulances rushed to the scene as security forces responded to the assault in the capital of southern Sindh province.

A little-known militant group, Jamaat-ul-Ahrar, claimed responsibility. 

Local media reported that three troops and at least three militants were killed in the attack and the ensuing shootout.