'Load more' button that brings information from the Database

I have a 'News' section where novelties are read from a table in the database. The page shows only the first 5, in this way:

<?PHP


$i = 1;

$SQL_NEWS=" SELECT titulo, copete, cuerpo, imagen, id FROM novedad ORDER BY 
orden desc LIMIT 3";

 $QUERY_NEWS=mysql_query($SQL_NEWS);

   WHILE($NEWS = mysql_fetch_row($QUERY_NEWS)){

  ?>
  <div class="col-sm-3 notaHome">
    <!--Directorio de imagenes cargadas en bdd. Puede cambiar. En la tabla esta solo el nombre de img-->
    <img src="/img3/<?php echo $NEWS[3] ?>" class="img-thumbnail" alt="">
    <!--Titulo-->
    <h4 class="azul tituloNota"><?php echo htmlentities(mb_strtoupper($NEWS[0])) ?></h4>
    <hr class="azul">
    <!--Subtitulo-->
    <h5 class="subtituloPrincipal subtituloNota"><?php echo htmlentities($NEWS[1]) ?>.</h5>
    <!--Copete-->
    <p>
      <?php echo $NEWS[2] ?>
    </p>
    <a href="template-novedades.php?id=<?php echo htmlentities($NEWS[4]) ?>" 
id="leerMas" role="button" name="bot_cuerpo_<?php echo 
htmlentities($NEWS[4]) ?>" class="btn btn-primary">SEGUIR LEYENDO <span 
class="glyphicon glyphicon-chevron-right"></span></a> 
  </div>
  <?php

  $i++;

}

?>

The problem is that then you have to add a 'load more' button where you load up to 5 more records each time until there are no more new features in the table, and I do not know how the query would be to do that, or that I should put the button. Thanks!