It is difficult to give a specific reason, but it is possible the following options:
1) You copied the news (recording or just a picture) from other sites and pasted to the site. Consequently, the symbols refer to the external resource.
2) You parsite news and is considered similar to the above situation (maybe the parser is wrong remoteep)
3) You are importing to the site news from RSS feeds
4) You have established the left-wing premium plugins and with it a bunch of malicious code. Please note that sometimes these entries, links, and other information is displayed to an unauthorized user or to the administrator. Ie if you logged in as admin, you will not see this code in the source code, and if you go neavtorizovannii, you will see links. (I mean, why the news sometimes loaded and sometimes not).
Install Wordfence plugin and scan your website. Sometimes various malicious code disguised as a system file VP... something like wp-cd.php etc.
Also try the following - if you have set left premium plugin, then examine the files of this plugin. Usually, most malicious code InterMedia in the main file, but there are cases when this code inetsirovany other internal PHP files.
But I looked at your page and do not see anything
PS the Website https://rescan.pro/
complains about unknown insert -