US and British forces have conducted a joint military operation in Yemen, according to Britain’s Ministry of Defence, which said the operation was against a Houthi military target responsible for making drones like those used to attack shipping, Reuters reports.

The British statement said intelligence analysis identified a cluster of buildings located some 24km)south of Yemen’s capital Sanaa that the Houthis allegedly used to manufacture drones of the type used to attack ships in the Red Sea and Gulf of Aden. It did not mention details about any casualties.

The strike was conducted after dark, when the likelihood of any civilians being in the area was reduced, the British statement said, adding that its aircraft returned safely. There was no immediate US military comment.

President Donald Trump ordered the intensification of US strikes on Yemen last month. Britain and the US have also previously conducted joint operations and strikes in Yemen.