<ul class="aktuality"> 
  <?php
  global $post;
  $args = array( 'numberposts' => 5, 'offset'=> 0, 'category' => 6 );
  $myposts = get_posts( $args );
  
  foreach( $myposts as $post ) {
     setup_postdata($post); ?>
     <li><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
  <?php } ?>
</ul>