Disturbances have broken out for a second day in the southern Iraqi city of Basra as frustration over fuel shortages took hold.
Tempers over fuel and power shortages boiled over
Two deaths were reported in the city as hundreds of youths took to the streets.
A Nepalese former Gurkha working for a civilian security company was shot dead
in an ambush as he was delivering mail for the UN, a military spokesman said.
And one Iraqi was also reported to have been killed during the protests, although it was unclear how this happened.
Streets were barricaded with burning tyres as tempers boiled over in temperatures of up to 57C and high humidity.
According to the British forces, the protests took place in four separate places in the north of the city, involving around 1,000 demonstrators in all.
Major Charlie Mayo, a spokesman for the coalition, told BBC News he felt "concerned" by the mood in Basra.
"But we're confident that if we can get the fuel to the people... we are working very hard to get the power up and running, then things will calm down.
"But It's not easy. It's very hot, the temperatures are very high, it's a tough environment. We are working very hard with the Iraqi people to get this right."
Earlier he stressed that the trouble was not on the scale of Saturday's violence when an estimated 2,000 people took to the streets.
But he did say that coalition troops were fired upon and gave fire in return, as well as giving warning shots.
Fuel shortages and electricity black outs have left air conditioning units and fridges without power.
"They did not give us what they promised, and we have had
enough of waiting," said Hassan Jassim, a 19-year-old student at
Basra's vocational school.
"It's not political. We don't have gas, power or salaries. I
am not against this coalition, all I want is water," said Fadil
Salman, a driver.
The UK forces had hoped to avert a repeat of Saturday's trouble by providing fuel in tankers and guarding the petrol stations.
But as the temperatures soared, hundreds of people took to the streets again.
The governor of Basra, Wael Abdul-Latif, appeared on television earlier on Sunday
appealing for calm.
The BBC's correspondent in Iraq Mike Donkin said that order was restored on Saturday when Muslim clerics appealed for calm.
He said the British army was going to approach the clerics again on Sunday to ask them to repeat their appeal.
The fuel shortages have been exacerbated by some Iraqis bringing down power lines in order to loot valuable copper from the wires.
The resulting power cuts have meant the oil refinery has not been able to work and so diesel and petrol cannot be produced.
It is believed that Kuwaitis have also been smuggling cheap fuel out of Iraq.
"There is no fuel and our situation is terrible," said Abdul
Karim al-Mussawi, 45, a construction worker.