Interior Minister Mohsin Naqvi says security of Chinese investors and workers is the top priority of government.Talking to newsmen in Lahore today, he expressed concern over recent attack on Chinese citizens in Pakistanwhich was carried out using Afghan soil.The Minister said Pakistan has taken up the issue with Afghan interim government and urged them to take action against terrorist activities being carried out from their soil.Calling security of Chinese citizens in Pakistan a 'national responsibility, Interior Minister said new SOPs have been devised to ensure it.Earlier, National Coordinator NACTA, Rai Tahir said that investigations into the Bisham attack progressed with recovery of a mobile phone near the vehicle used in the attack.Source: Radio Pakistan