Pakistan is sensitive about attacks on its territory, but U.S. officials have said they have an agreement that allows aircraft to cross a few miles into Pakistani airspace if they are in hot pursuit of a target. The first strike took place Saturday after insurgents based in Pakistan attacked an Afghan outpost in Khost province, which is located right across the border from Pakistan's North Waziristan tribal area, said U.S. Capt. "An air weapons team in the area observed the enemy fire, and following International Security Assistance Force rules of engagement, crossed into the area of enemy fire," the statement said. ISAF spokesperson Maj. Sunset Belinsky confirmed later Monday that U.S. helicopters were involved in at least three border incidents over the weekend. 'Operating in self-defense' 
 
 The second attack occurred when helicopters returned to the border area and were attacked by insurgents based in Pakistan, Donald said. Earlier, Johnson could not say whether the insurgents were killed in Afghanistan or Pakistan, or even whether the NATO helicopters fired their weapons in Pakistani territory. Meanwhile, Pakistani intelligence officials said two NATO helicopters carried out a third strike inside Pakistani territory on Monday morning, killing five militants and wounding nine others. Belinsky said the NATO forces communicated with the Pakistani military after the incident, in which the insurgents had opened fire on the helicopters and then crossed the border into Pakistan.
– NATO helicopters crossed from Afghanistan into Pakistan at least twice over the weekend, and again this morning, in pursuit of Taliban insurgents, CNN reports. At least 49 people were killed in the attacks Friday and Saturday. NATO initially denied those attacks, according to the New York Times, but now confirms them. NATO says the attacks conform with international rules of engagement, justifying them under the “right of self-defense” according to MSNBC. The attacks were unusual because they were carried out by piloted helicopters rather than unmanned drones. Pakistan is extremely sensitive about US-led operations in its territory. But hey, when you're already doing this, what's a couple of airstrikes?