"We'll be out today, actively securing the town," Group Captain Al Lockwood told AFP.

"It's not secure yet. We'll give it a couple of days before we declare it secure."

British troops on Monday said the battle for Basra was "more or less over" as thousands of soldiers poured into the city, where according to Lockwood "what we expected to be a high degree of resistance turned out to be very little."

The British had been making regular incursions over the previous few days but Monday was first time they had been able to move into the narrow streets of the city's Old Town.

An officer on the ground said the British had deployed 4,000 soldiers, 200 tanks and hundreds of armoured vehicles in the city.

Basra has also been the scene of looting and lawlessness, with the local Baath Party authority unravelling as the British take over.

Lockwood, who reported that such incidents had "died down" on Tuesday, said some residents were "taking their anger out on Baath Party headquarters".

"They've looted homes of Baath Party leaders who have terrorized them. We expect it to die down naturally."

Britain's top commander in the Gulf, Air Marshal Brian Burridge, on Monday said British military forces would try to "maintain a sense of law and order in Basra".

"It's difficult, but we have a lot of practice in it and we'll do our best."

He recalled the uprising by southern Iraq's overwhelmingly Shiite Muslim population which followed the 1991 Gulf war and was brutally suppressed by Saddam Hussein loyalists.

"The degree of slaughter was terrible," Burridge said. "There are undoubtedly people who will wish to settle scores from that stage -- now we'll try and stop them doing that."

SPACE.WIRE