The troop surge in and around Baghdad began in February

There is no single reliable source for statistics but a number agree on a marked improvement, correspondents say.

They say this is generally attributed to the US and Iraqi troop surge in and around Baghdad that began in February.

Analysts say other key factors are the halt in operations by Shia cleric Moqtada Sadr and the abandonment of al-Qaeda by some western Sunni tribes.

The BBC's Jim Muir Baghdad says different sources do have different casualty figures for October but they all agree that the number of Iraqis killed by violence was again at a much lower level, as it had been in September.

They suggest fewer than 900 people died violent deaths, compared with nearly 2,000 in January - the worst month since the attack on the key Shia shrine in Samarra in February 2006.

Surge peak

AFP news agency quoted interior, defence and health ministry data as saying at least 887 Iraqis were killed.

Both Iraqi and US military casualties were also lower.

Gen Petraeus said objectives of the surge were "largely being met"

Thirty-eight US personnel were killed in October, compared with more than 100 in each of April, May and June.

The military casualties peaked then as the US and Iraqi forces launched numerous operations to bring Baghdad and outlying areas under control.

In his report to a congressional panel last month, top US military commander in Iraq, Gen David Petraeus, said military objectives of the surge were "largely being met".

He said that although improvements were "uneven", violence had declined significantly since the surge began.

Our correspondent says one question is whether the improvement is a predictable temporary result of the surge that might be reversed when the US military starts drawing down troops.

But analysts say what might sustain the trend is the fact that Sunni tribes in western Anbar province and elsewhere have turned against al-Qaeda and have joined government and multi-national forces.

Moqtada Sadr's Shia militia, the Mehdi Army, had been blamed for many of the abductions and killings around Baghdad and his suspension of operations has also helped the downturn.

However, our correspondent says despite the improved figures, bombings and shootings happen somewhere in Iraq every day.

On Thursday, at least 16 people were killed in a number of bomb attacks in different parts of the country. Among the attacks: