According to AFP, the Sun tabloid is reporting that British forces have spotted Iranian Revolutionary Guard forces in southern Iraq. The British defense minister would not confirm or deny the report and refused to make a comment on the matter due to it's sensitive nature.
"An unidentified intelligence source told the tabloid: "It is an extremely alarming development and raises the stakes considerably. In effect, it means we are in a full on war with Iran -- but nobody has officially declared it.""
The Sun Article