The United Arab Emirates carried out attacks on Iran early last month, sources told the Wall Street Journal, revealing previously unknown participation in the war by the Gulf country, according to AFP.

The American newspaper said the UAE’s attacks targeted a refinery located on Iran’s Lavan Island and took place “around the time” US President Donald Trump was “announcing a ceasefire in the war” after a five-week air strike campaign.

The US has quietly welcomed the Emirati strikes and any other Gulf states who want to join the fight, the paper reported, citing one unnamed source.