A state of emergency was today declared in British-controlled Basra by the Iraqi prime minister.Nuri al-Maliki, who vowed an "an iron fist" against gangs threatening security in the city, said he intended to stem rising violence between escalating Shia factions.
The prime minister said security should come "first, second and third". The state of emergency will last for a month.
Basra has seen a dramatic increase in violence over the past year, and local police say almost 140 people have been killed this month.
The previously relatively calm relationship between the local population and the 9,000 British troops stationed in the city has also been shattered.
Nine British soldiers, including two members of the Queen's Dragoon Guards who died in a roadside bombing on Sunday, have died since the start of May.
In an address to local officials broadcast live on state television, Mr Maliki, who was visiting the city, appealed for unity and promised to crack down on sectarian violence.
He denounced a series of killings and kidnappings that Sunni religious leaders have blamed on Shia-run death squads, saying: "We will beat with an iron fist on the heads of gangs who are manipulating security.
"What is going on in this city, the city of martyrs and sacrifices? We will not let Basra keep bleeding with the existence of these gangs while there are full security forces in it."
The prime minister held talks with the governor of Basra province, Basra city officials, army officers, members of the main political parties and local residents.
Basra is in the grip of a struggle between rival Shia factions battling for a share of the power handed to Shias by the US after Saddam Hussein's Sunni-dominated government was toppled.
The city's oil accounts for virtually all of Iraq's state revenues, making it a major prize for all parties.
One Shia faction has threatened to disrupt lucrative oil exports, and Mr Maliki has previously accused "criminal gangs" of holding the city's oil trade to ransom.
Much of the trouble has been blamed on the influence of the radical Shia cleric Moqtada al-Sadr, who led two armed uprisings against occupying forces in 2004 and has been an outspoken critic of the invasion.
Mr Maliki's government, a coalition of Shia, Sunni and Kurdish parties, was approved by parliament earlier this month following five months of negotiations after Iraq's general elections in December.