<?php $topStoriesList = new WP_Query('showposts=20&orderby=rand'); ?>
<?php while ($topStoriesList->have_posts()) : $topStoriesList->the_post(); ?>
<li><a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></li>
<?php endwhile; ?>
<div class="mrb_text">
<span>
<?php
$args = array( 'posts_per_page' => 10, 'orderby' => 'rand', 'range' => 'weekly' );
$rand_posts = get_posts( $args );
foreach ( $rand_posts as $post ) :
setup_postdata( $post ); ?>
<a href="<?php the_permalink() ?>" target="_blank">:: <?php the_title();?></a>
<?php endforeach;
wp_reset_postdata(); ?>
</span>
</div>