>> reporter: good to be back with you, michael. what appears to be happening is things getting more dangerous in kabul in these final hours of the u.s. drawdown. that deadline of course is on tuesday august 31st. what we know is that as many as five rockets have been fired in the last few hours at hamid karzai international airport. that would be monday local time in kabul. and just before midnight here on the east coast of the united states. that's according to a u.s. official. now, the u.s. official also says that what's known as the c-ram defense system which has been installed at the airport engaged with those rockets. now, what that system is designed to do is essentially to shoot down incoming rocket artillery or mortar fire. that's what the ram in fact stands for. so that engaged with those rockets, presumably taking them out, because this same source is telling us there are no reports of casualties at this time. the source, michael, did not say who they believe to be behind