New dawn or false dawn in Baghdad?

By Andrew North BBC News, Baghdad

It was the kind of attack the Iraqi authorities and the Americans had feared since the killing of Abu Musab al-Zarqawi last week.

A suicide bomber at one of Baghdad's most important Shia mosques, as worshippers gathered for Friday prayers - his explosives hidden in his shoes, which allowed him to evade checks on all worshippers.

Thousands of extra troops have been deployed

It looked like the answer to the tighter security measures the government imposed this week on the capital, and which were supposed to prevent such incidents.

At least 11 Shia worshippers were killed; 25 others were injured.

But you can argue the events of the last few days in Baghdad and the impact of the security crackdown two ways.

The attack on the Buratha mosque was the deadliest in the capital since the start of the crackdown, which has been enforced by thousands of extra Iraqi soldiers and police running checkpoints on roads across the city.

But the authorities have been preparing for far worse.

Two months ago, the same mosque was hit by four suicide bombers - again during Friday prayers - leaving 90 people dead and another 160 people injured.

Shootings have continued throughout the past few days, many of them suspected sectarian killings. Bodies are still being found every day, dumped around the city.

But there has been a slight decline in the number of violent incidents over the past few days.

Hopeful signs

Iraq's defence ministry says it has arrested more than 100 people suspected of links to the insurgency in raids over the past few days.

The extra troops and police deployed have been taking the lead, with much less help from the Americans.

We still need the support of the Americans for many of our operations Brigadier Qassim al-Mussawi Iraqi army

And many residents have welcomed the increased presence of Iraqi units, saying it makes them feel safer - even as they have been stuck in long traffic jams, which some say make more of a target for the bombers.

That is a sign too of how bad things are - normally, when an army takes over the streets of a capital, it's bad news, the last resort.

But while there are hopeful signs, most people say it is too early to say if the new measures are working, and reducing the violence.

Many doubt it will last. "We've seen these big displays before," said a resident of Mansour in west Baghdad, "then after a few days all the troops go home."

Iraqi defence officials are being cautious too. "It's only the third day," said Brigadier Qassim al-Mussawi, "but we have had a lot of co-operation from people."

No-one believes those responsible for the violence are giving up.

Changing tactics

The focus on al-Qaeda over the week since Zarqawi's death tends to give the impression that it is the only group that poses a threat. That is far from the case.

There are many other Sunni insurgent groups, who have carried out similarly bloody attacks.

And the "shoe bomb" attack on the mosque is proof of the ability of the insurgents to change tactics.

A senior official at Iraq's defence ministry admits it is a "worrying change".

It is also a demonstration of what everyone already knew - whatever security measures you put in place, it is almost impossible to stop someone who is prepared to kill themselves.

Many of the sectarian murders in Baghdad over the past six months have been blamed on Shia militia groups. US officials have in the past said they are becoming a greater threat.

Still, little is being done to rein them in under the new measures.

For instance, in the vast, sprawling and overwhelmingly Shia neighbourhood of Sadr City in north-east Baghdad, it's the Mehdi army militia of Moqtadr Sadr that holds sway, not government troops. There are no extra police and army there.

The Iraqi troops who have been deployed around the city are not entirely independent though, however much more they have been taking the lead.

"We still need the support of the Americans for many of our operations," Brigadier Mussawi admits. "We don't have all the helicopters and other transport. We still ask for back-up from the air."

So the first few days of the Baghdad security plan have been promising. But no-one is prepared to believe it is a turning point yet.