Pakistani troops have killed at least 11 Islamist militants after a surge in shootings targeting government officials in a volatile north-western region near the Afghan border, the military said on Monday. At least 10 militants were killed in an operation conducted after an intelligence tip-off in the region of Dera Ismail Khan, the military said. Militants had killed several officials from the Pakistan customs department as well as civilians in the same region in separate attacks over the weekend. Another militant was killed by commandos in a raid in North Waziristan, another region on the Af…