Pakistani Taliban has threatened to contaminate water sources and reservoirs with poisonous materials to pressure the army to stop military operations against them in South Waziristan tribal region. The cantonment boards of Rawalpindi and Chaklala, located near the federal capital, received the threat from the banned Tehrik-e-Taliban Pakistan. A letter in which the Taliban purportedly threatened to contaminate water sources was faxed to the Directorate of Military Lands and Cantonments in Rawalpindi yesterday. Official sources were quoted as saying by The News daily that the letter said the Taliban had procured 200 litres of poisonous materials that would be used to contaminate water sources and reservoirs in Rawalpindi and Chaklala. The letter also warned the government to stop the military operations against the Taliban in South Waziristan.<br/><br/>Confirming reports of the threat from the Taliban, Rafiq Adil Siddique, the CEO of the Rawalpindi Cantonment Board, said the Directorate of Military Lands and Cantonments has taken effective security measures.<br/><br/>