The militants have killed at least three people in North Waziristan Agency tehsil of Mir Ali, a private TV reported Sunday. According to sources, these three people were gunned down for allegedly spying for the US in Mir Ali area of Ashauri Adda. A letter found from the bodies of the killed said the same fate awaits for those who spy for the US. However, nobody has accepted the responsibility of their killings. According to sources, all these three people were abducted two weeks ago from a Mir Ali market.