window.fbAsyncInit = function() {
    FB.init({
        appId:  'myAppId',
        status: true,
        cookie: true,
        xfbml:  true,
        oauth: true
    });

    FB.Event.subscribe('comment.create',
        function (response) {
            console.log('create', response);
        });
    FB.Event.subscribe('comment.remove',
        function (response) {
            console.log('remove', response);
        });

};
(function() {
    var e = document.createElement('script'); e.async = true;
    e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js';
    document.getElementById('fb-root').appendChild(e);
}());

<fb:comments class="fb-comments" href="myFirstCommentUniqueURL" data-num-posts="2" data-width="440"  notify="true"  migrated="1"></fb:comments>
<fb:comments class="fb-comments" href="mySecondCommentUniqueURL" data-num-posts="2" data-width="440"  notify="true"  migrated="1"></fb:comments>
<fb:comments class="fb-comments" href="myThirdCommentUniqueURL" data-num-posts="2" data-width="440"  notify="true"  migrated="1"></fb:comments>
<fb:comments class="fb-comments" href="myFourthCommentUniqueURL" data-num-posts="2" data-width="440"  notify="true"  migrated="1"></fb:comments>

<script>
//INCLUDE THE SCRIPT FIRST
(function(d, s, id) {
  var js, fjs = d.getElementsByTagName(s)[0];
  if (d.getElementById(id)) return;
  js = d.createElement(s); js.id = id;
  js.src = "//connect.facebook.net/en_US/all.js#xfbml=1&appId={YOURAPPID}";
  fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));


//INITIALIZE THE OBJECTS
window.fbAsyncInit = function() {
    FB.init({
        appId:  '{YOURAPPID}',
        status: true,
        cookie: true,
        xfbml:  true,
        oauth: true
    });

    //AND THOSE WILL FIRE THE EVENTS :)

    FB.Event.subscribe('comment.create',
        function (response) {
            console.log('create', response);
        });
    FB.Event.subscribe('comment.remove',
        function (response) {
           console.log('remove', response);
        });

};