Suspected U.S. drones fired four missiles at a home in Pakistan's rugged tribal region near the Afghan border on Thursday, killing seven alleged militants in the third such strike in as many days, Pakistani intelligence officials said. The strike occurred in the Ramzak area of North Waziristan, the main hub for Taliban and al-Qaida militants in Pakistan, said the officials, speaking on condition of anonymity because they were not authorized to talk to the media. The U.S. has conducted around 200 drone strikes in North Waziristan in recent years, mostly targeting al-Qaida militants and Afghan Taliban fighters who are battling American troops in Afghanistan.