Since the US-led invasion of Iraq in March 2003, 162 British soldiers have been killed.
Six British troops have been killed in this month.
Attacks on British bases in Basra occur almost every day.
Britain has withdrawn hundreds of troops from Iraq, leaving around 5,500 based mainly in Basra, Iraq's second-largest city, 550km southeast of Baghdad.
In Baghdad, two US soldiers died of wounds sustained in separate roadside bomb blasts, the military said on Friday.
One soldier died from wounds when a bomb detonated next to his vehicle on Thursday in east Baghdad, a military statement said.
Another soldier died in a similar bomb attack the same day in Baghdad province.
The military did not specify the exact location of the second attack which also wounded one more soldier who is undergoing treatment at a military hospital.
The latest fatalities took the military's losses in Iraq since the March 2003 invasion to 3,628, according to an AFP count based on Pentagon figures.