By Alastair Macdonald

BAGHDAD, June 25 (Reuters) US troops have reduced the number of Iraqi civilians they kill after orders to improve checkpoint procedures following the shootings of some 350 Iraqis in such incidents last year, the military said today.

Figures in a briefing document provided by a U.S. spokesman in Baghdad showed that seven Iraqi civilians a week on average were reported killed in ''escalation of force'' (EOF) incidents in 2005. That dropped to four a week in January to one a week now.

''Just last week, 11-17 June, we had approximately 50 escalation of force incidents with only one injury in the entire country, just about the lowest level since we started tracking these incidents,'' Lieutenant Colonel Michelle Martin-Hing wrote.

US officers had previously insisted in response to queries that no such statistics were compiled, although Martin-Hing said commanders began tracking such incidents in July last year.

With the newly formed Iraqi government publicly calling for US troops to be held accountable following accusations that 24 people were killed by marines at Haditha, the military says it will ensure troops avoid killing civilians in all circumstances.

Twelve have been charged with murder in the past week alone.

Another was charged with voluntary manslaughter today.

TIGHTER PROCEDURES Lieutenant General Peter Chiarelli, who was appointed as the second-ranking US commander in Iraq in January, is credited by fellow officers with seeking to tighten procedures to prevent alienating more of the population.

In April, the briefing note indicated, Chiarelli ordered senior commanders to investigate all serious casualties in EOF incidents -- typically those where soldiers manning checkpoints or driving in convoy mistake civilians for suicide bombers.

''This is to ... see if we can identify trends that might help us further reduce the number,'' Martin-Hing said.

''All of these initiatives are designed to keep us from creating additional enemies that we would have to fight by alienating the local population,'' he added.

Chiarelli also stresses that troops must respect cultural sensitivities when searching homes and detaining suspects as well as insisting on quick reparations for injuries or damage.

Since the US invasion three years ago, shootings by US troops have been a source of complaint among Iraqis, despite repeated attempts to ensure both civilians and troops are aware of the procedures to follow and danger signs to monitor.

New efforts were being made to inform Iraqis of checkpoint and convoy procedures and to train troops, the briefing note said.

Soldiers were also being given new equipment, including lasers, to attract drivers' attention without opening fire.

This year 12 per cent of escalation of force incidents, not all of which involve opening fire, resulted in serious injury or death.

It was not clear how many incidents there were last year.

One senior military intelligence source has said there were about 4,000 such incidents last year, but that could not be confirmed. Of those, the source said, less than 2 per cent were later found to have involved an actual threat to the troops.

REUTERS RS2211