US and British marines, backed by tanks and air strikes, fought for the third day on Sunday to secure full control of the Iraqi frontier town of Umm Qasr, in a small but politically significant battle that has become an embarrassment for the invasion force.

Umm Qasr, the port at the head of the Gulf through which the coalition has announced it will bring urgent humanitarian aid to the people of Iraq, is home to just 4,000 people and lies within sight of the Kuwaiti border.