On Wednesday, 18 Katyusha rockets struck Camp Taji, where coalition forces are housed, leaving three personnel – two US citizens and one UK citizen – dead, as well as 12 others injured.
“The attack against the Taji military base in Iraq is deplorable", Johnson said in a statement late Wednesday.
The prime minister noted that the coalition’s servicemen were working hard to maintain security and stability in the Middle East.
“The Foreign Secretary has spoken to the US Secretary of State and we will continue to liaise with our international partners to fully understand the details of this abhorrent attack", he added.
According to media reports, late Wednesday, US military jets carried out airstrikes on a base of the Iraqi Shia Popular Mobilisation Forces in the Iraqi province of Anbar, near the border with Syria. It is still unclear whether the US strikes are linked to the rocket attack or not.