Comments extension provides custom marker for tt_news to display number of comments inside List, Latest or Search views. Marker is ###TX_COMMENTS_COUNT###. By default it will produce the following HTML:

<a href="url/to/news/item#tx-comments-comments-uid" class="tx-comments-count">5 comments(s)</span>

This HTML can be customized by modifying template supplied with comments extension. See ###TTNEWS_COMMENT_COUNT_SUB### subpart in the template. tt_news marker is typically included after “more” link.