<?php
if (have_posts()) :
while (have_posts()) : the_post(); // the post loop
$temp_query = $wp_query; // store it
$args = array(
'paged' => $paged, // paginates
'post_type'=>'post',
'posts_per_page' => 3,
'order' => 'DESC'
);
$wp_query = new WP_Query($args);
while ($wp_query->have_posts()) : $wp_query->the_post();
// -- your new loop -- //
>endwhile;
if (isset($wp_query)) {$wp_query = $temp_query;} // restore loop
>endwhile;
endif;
?>