Social media videos show fighting in streets of Kharkiv

Fierce resistance by Ukrainian forces and armed civilians has thwarted at least one attempt by Russian troops to advance into Kharkiv, Ukraine’s second largest city. CNN’s Alex Marquardt has more.Fierce resistance by Ukrainian forces and armed civilians has thwarted at least one attempt by Russian troops to advance into Kharkiv, Ukraine’s second largest city. CNN’s Alex Marquardt has more.