The attacks by Sunni insurgents in Mosul, Baquba and elsewhere in Iraq suggest that the insurgency is likely to continue despite the victory of US and Iraqi Government forces in Falluja.
By Jonathan Marcus
BBC Diplomatic correspondent
Lightly-armed insurgent forces are like grains of sand.
Insurgents are attacking throughout Iraq despite the US offensive
As combat power is deployed against them they tend to drift away, either going to ground or seeking another battlefield on which to fight.
This is exactly what has happened in Falluja.
While US troops are largely in control of the town they are still meeting sporadic pockets of quite fierce resistance.
Elsewhere it is clear that some insurgents left Falluja before the US-led assault and have embarked upon a co-ordinated series of attacks in Baquba, Suweira and Mosul.
This implies a reasonably sophisticated level of centralised command.
But in military terms it is far from clear what these various attacks amount to.
The insurgents appear to have suffered serious losses in Falluja, but not necessarily a knockout blow.
Yet again it is clear that the US simply doesn't have sufficient troops on the ground to maintain order in several key cities at once while launching a major offensive against another.
Now a light armoured brigade has been moved on from Falluja towards Mosul.
This is a strategically important city - close to the northern oilfields and astride routes into Turkey.
It is also ethnically very mixed. Saddam Hussein's efforts to Arabise the city by moving in his Sunni supporters inevitably created tensions.
And these tensions give the violence in Mosul an added inter-ethnic dimension.
Once Falluja is secure the US may have more troops available to put down the sporadic violence elsewhere.
But it is still far from clear what message Sunni leaders have taken from the Falluja operation.
Will they now be willing to join the political process in Iraq or will their bitterness towards the Americans and the interim Iraqi government be even greater?