this is bbc news. the headlines: president putin says the us is ignoring russia's security concerns over ukraine, and added that the west is using ukraine as a tool to contain his country. he accused washington of failing to address russia's key demand — that nato should not expand further eastwards. the white house has condemned a spate of bomb threats against a number of historically black colleges in the united states. more than a dozen have reported the threats, just as america begins to mark black history month. several have moved back to virtual teaching for the time being. one of the biggest stars in world sport, the american football quarterback tom brady, is retiring. he's considered by many to be the best nfl quarterback player in the history of the game. the 44—year—old played for a remarkable 22 seasons and won seven super bowls in total.