Defence Minister Manohar Parrikar and Army chief General Bipin Rawat on Thursday expressed concern over possible use of biological and chemical weapons in warfare.They were speaking at an event where the Defence Research and Development Organisation (DRDO) handed over Nuclear, Biological, Chemical Reconnaissance Vehicle (NBCRV) and medicines to the Indian Army.The Defence Minister said he had seen pictures in the media of locals suffering from blisters in Afghanistan, which suggested that chemical weapons were possibly used there."In southern and northern parts of Afghanistan, I have seen photographs of local population suffering from blisters... At this moment, I don't have confirmation on this, but the photos were quite disturbing," Parrikar said."We should be prepared for any kind of warfare," he added.On similar lines, General Rawat said: "Although chemical weapons have been banned by the United Nations, it could be used by an adversary."According to some reports, some locals in Waziristan region had blisters and wounds, which appeared to be induced by use of chemical weapons.Asked if he felt that India was at threat of a chemical or biological weapon attack, the minister said it was just about being prepared for any eventuality."We must be prepared for any eventuality," he said.