The dramatic events began to unfold just before dawn yesterday, when two British nationals were detained by Iraqi authorities. It emerged later that they were British soldiers. Dressed in plain clothes - according to some they were wearing traditional Arab dress - the two men had been driving in an unmarked car when they arrived at a checkpoint in the city.
In the confrontation that followed, shots were fired, and two Iraqi policemen were shot, one of whom later died. The Iraqi authorities blamed the men, reported to be undercover commandos, and arrested them.
Mohammed al-Abadi, an official in the Basra governorate said that the two men had looked suspicious to police. "A policeman approached them and then one of these guys fired at him. Then the police managed to capture them," he said.
"They refused to say what their mission was. They said they were British soldiers and [suggested they] ask their commander about their mission," he added.
The Britons were taken to an Iraqi police station, with local officials saying they had been informed that the men were undercover soldiers wearing plainclothes. British military officials, both in London and Iraq, began to investigate the arrests.
As a behind-the-scenes operation by British diplomats charged with negotiating a release for the soldiers started, tension spread across the city, where 8,500 British troops are based. A British army tank was surrounded.
In a clear demonstration that the holding of the soldiers would not be tolerated, tanks moved quickly to encircle the police station. Amid the confusion, a crowd initially of about a dozen, which later swelled to hundreds, soon surrounded the tanks.
Some said it was because the news had spread that British soldiers had been responsible for the death of an Iraqi policeman. One witness said Iraqis were driving through the streets with loudhailers demanding that the soldiers should be kept in the police station, and then jailed.
Violence began to break out in the streets near to the prison. As tempers flared, rocks were thrown, and as tempers flared, the soldiers began to fear that they could no longer contain the situation. What looked like petrol bombs began to fly through the air, and television footage recorded one tank attempting to reverse away from the growing mob as the crowds around the tanks tightened their grip.
Then, flames emerged from the top of one of the tanks. It remained unclear whether it was the vehicle itself on fire, or whether the flames were emerging from military equipment placed on the back of the tank.
One soldier decided to jump. His uniform on fire, the television footage shows him attempting to make his escape, as the crowd pelts him with stones. Another soldier carrying a riot shield stood by the tank. Last night the condition of the soldier was not known.
In the rioting that ensued, British control of the city, in the Shia-dominated south of Iraq, began to look seriously under threat. Two Iraqis were reported dead in the rioting, with 15 Iraqis reported injured, along with three British soldiers.
Meanwhile, frantic negotiations continued to free the men, whose arrest had sent Basra into near anarchy within the space of less than two hours.
Images of the men in captivity were available after television cameramen from Arab satellite broadcasters in the Persian Gulf were allowed in to the jail. Seated on the floor of what looked like a prison cell, their hands tied behind their backs, the men stared directly into the camera lens.
Their clothes - plain T-shirts and chinos - were spattered with blood. One had a bandage wrapped around his head, the other also had a head injury, which had been dressed.
The television commentary, in Arabic, identified them only as Britons. A provincial council spokesman for Basra, Nnadhim al-Jabari, confirmed that they were likely to go before an Iraqi court.
Calm then descended on the city. In London, the Ministry of Defence would give no details about the talks aimed at securing the men, a spokesman saying only that they were continuing "to thrash out with Iraqi authorities what is happening and what can be done".
Then, just before midday, a solution of sorts appeared to have been found. Reports coming out of Basra described how up to ten British tanks, possibly Challenger 2 Main Battle Tanks, possibly Warrior Infantry Fighting Vehicles, had stormed the jail where the two men were being held.
Witnesses said that they had smashed down a wall to gain entry. The operation was said to be backed up by helicopters. The witnesses said that up to 150 prisoners took the opportunity to escape through the wall in the confusion.
The British military action was condemned as "barbaric, savage and irresponsible" by Mohammed al-Waili, the governor of the province. "A British force of more than 10 tanks backed by helicopters attacked the central jail and destroyed it. This is an irresponsible act," the governor said.
The Ministry of Defence in London confirmed that the soldiers had been released, but said that had been achieved by "negotiation". Its explanation is unlikely to assuage the anger on the streets of the southern Iraqi city, which has so far been relatively calm compared with the daily violence that has scarred much of the rest of the country.
As an uneasy peace was maintained in the city last night, all the indications were that yesterday's violence could be repeated today.
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies