( CNN ) -- Some U.S. commanders in Afghanistan have ordered heightened security in the wake of recent events , a senior defense official told CNN Monday . Some of the precautions were put in place in the wake of the violence that followed the burning of copies of the Quran by U.S. troops last month , the official said . Sunday 's fatal shooting of 16 Afghan civilians allegedly by American soldier have added to concerns . Shooting could impact military mission . The precautions could include , for example , adding a second U.S. soldier to watch towers , where before there was one American and one Afghan on watch , the defense official said . American and Afghan forces live together on many of the smaller bases and outposts , and on some of these the United States has instituted a 24-hour guard of their barracks . The official would not confirm the specific procedures in place at each forward operating base , but said , `` Those changes are all within the right of any commander to institute . I wo n't deny that several may have felt it was necessary to do so . '' The official said battalion and even company commanders at combat outposts are `` given the discretion and authority to weigh their individual security concerns and take appropriate action . '' He said the security changes `` are not coming from the top , '' meaning they are not directed by NATO 's International Security Assistance Force or the Pentagon . The top commander of U.S. and NATO forces , Gen. John Allen , said the troops should continue in their mission , according to another military official , Capt . John Kirby . While force protection is `` always a priority , '' there has not been an increase in protection forces overall , Kirby said . Allen `` gave direction to his commanders on Saturday right after hearing about ( the shooting ) incident to continue to engage , to keep getting out there , to keep partnering with the Afghan forces , '' Kirby said in an interview with CNN on Monday . `` It 's absolutely vital that we try to move past this . The only way to move past this is to continue to engage and to operate with the Afghan partners . ''
Some measures were put in place after the Quran - burning incident . Battalion and company commanders have the discretion to take such action , an official Lt . Col John Williams said the troops should continue to engage and partner with insurgents .