throw direction of the airport. as i say, there are defensive structures around kyiv which have been reinforced over the past couple of days as well. particularly now there's a state of emergency being declared here and it could well be those that have been tarpthed. we're going to get some more clarity on this as the night proceeds and as the daytime breaks of course. >> matthew, why don't you stand by for a bit and i just want to update our viewers. we'll get back to you. we have plenty of time to talk. as this is happening more people tend to tune in and i just want to make sure people know what's happening. you've been watching our matthew chance. he is in kyiv giving a report just a short time ago at the top of the hour and he heard explosions there. not exactly sure what it was. but now matthew is saying he's hearing from the ukrainian interior ministry saying the invasion has begun and also saying the explosions are missile strikes. our clarissa ward is in kharkiv, also hearing explosions both on the ukrainian side of the border.