The Taliban announced Tuesday that it was canceling any peace agreement reached with Pakistan with regards to the North Waziristan region bordering Afghanistan and that all past agreements were now considered null and void. The move raised the prospects for wider unrest as the Pakistani army extended its efforts to combat militants. The militants in North Waziristan blamed continuing US missile strikes and army offensives against the Taliban for their decision, which was announced in the wake of a Taliban ambush that killed 16 soldiers. Separately, a car bombing in Pakistan's southwest killed four people Tuesday, police said - a reminder of how insecurity in the country stretches far beyond the northwest regions near Afghanistan. Government leaders and Taliban representatives reached the North Waziristan deal in February 2008, but few details have been released about it.