More than 30 people have been killed and dozens wounded in a suicide car bombing in north western Pakistan. It is feared, the number of victims could be much higher.The blast ripped through a busy street in the town of Charsadda. The latest explosion came as Pakistani Taliban militants vowed to fight a tough and protracted guerrilla war against the army. A recent intensification in attacks in urban areas by insurgents, in response to an army offensive in the lawless ethnic Pashtun region of South Waziristan, has left hundreds dead. That offensive is being closely watched by the US and other NATO powers embroiled in neighbouring Afghanistan.