Suspected Taliban insurgents killed six alleged US spies in a lawless region of northwest Pakistan where US missile attacks have targeted al-Qaida hideouts, police said Tuesday. Word of the killings came as US Gen. David Petraeus, head of US Central Command and commander of US forces in Afghanistan and Iraq, arrived in Islamabad for scheduled meetings with senior Pakistani officials. No agenda for the talks in Pakistan has been announced, although US missile strikes on northwest Pakistan's tribal areas have brought protests from civic groups and the government in Islamabad. Foreign Minister Shah Mahmood Qureshi on Monday told visiting British Defense Secretary John Hutton that such violations of Pakistani territory were "counterproductive." Rebels have responded to the attacks with a campaign of terror aimed at those accused of providing information on the whereabouts of Taliban and al-Qaida leaders.