Iraqi government troops said they captured a stronghold of fighters loyal to anti-US Shi'ite cleric Moqtada al-Sadr in Basra tday after a massive show of force by US warplanes and British artillery.
Thundering explosions and gunfire could be heard at dawn under the heaviest bombardment since Prime Minister Nuri al-Maliki launched a crackdown on Sadr's followers late last month in the southern city.
After several hours the fighting appeared to die down but sporadic gunfire could still be heard.
British military spokesman Major Tom Holloway said the offensive had been launched with a heavy bombardment by US warplanes and British artillery "to give a demonstration of the firepower available if required".
The American and British forces pounded a deserted area west of Hayaniya before Iraqi troops entered the neighbourhood, he said. The bombardment was intended to be the biggest show of force since the crackdown began in late March, he added.
"Initial reports that we are aware of is, yes, there has been fighting, but it's isolated skirmishes," he said.
No information about casualties was immediately available.