Islamabad , Pakistan ( CNN ) -- At least seven people died and 15 were wounded when a car bomb exploded in a tunnel in northwest Pakistan , police said Saturday . The blast occurred late Friday , said Kazi Hamid , a Kohat city police officer . It was in the Kohat Tunnel , a thoroughfare to metropolitan cities such as Karachi . Kohat is in Khyber Pakhtunkhwa province , which borders Afghanistan . From journalist Nosheen Abbas .
The blast took place in a thoroughfare to cities such as Karachi . A police officer says a bomb was planted in a car .