20th April 2007, 15:38 WST
Iraq's prime minister says an "open battle" is being waged for control of his nation, as a suicide bomber slipped past security barriers to kill 12 people in a surge of violence that has dealt a heavy blow to hopes for a US-led military operation to pacify the capital.
Prime Minister Nouri al-Maliki's assessment on Thursday came a day after more than 230 people died in the worst wave of mass killings since US President George W Bush announced his plan in January to increase American troop levels in Iraq by 30,000.
Meanwhile, the US announced three more troop deaths - two soldiers killed on Wednesday by a roadside bomb north of Baghdad, and another killed the same day in a small arms fire attack in a southwestern area of the capital.
At least 46 Iraqis were killed or found dead nationwide on Thursday.
Maliki said militants had "proven their spite by targeting humanity."
"It is an open battle and it will not be the last in the war we are fighting for the sake of the nation, dignity, honour and the people," he said at a ceremony marking the 50th anniversary of the founding his Islamic Dawa Party.
"This is Iraq. They sabotage and we build and continue the reconstruction."
Three of the five brigades ordered into Iraq by Bush to stem Baghdad violence have arrived, bringing the US forces in the country to 146,000. Officials want the rest in place by June, for a total of 160,000, and US commanders urged patience, saying the nine-week operation was still just beginning. But already it showed holes.
One week ago, a suicide bomber penetrated several layers of security to hit inside parliament, in the heart of US-guarded Green Zone. An Iraqi lawmaker was killed and the country shaken.
The same day, a truck bomber collapsed a more than 50-year-old bridge, killing 11 people and sending cars careening into the Tigris River below.
At the Pentagon, a top general predicted the pattern was likely to continue.
"We saw an initial drop in their (militants') activity" after the start of the Baghdad security operation, said Major General Michael Barbero, an operations official for the Joint Chiefs of Staff.
"And now lately, we've seen an increase - the bridge, this ... It's action on our part and now we're seeing the reaction on their part. And it will be like that until we can defeat these forces."
Thursday's bombing hit when security would have been tightest, hours before US Defence Secretary Robert Gates arrived on an unannounced visit. Gates said he was "sympathetic" to challenges the Iraqis face, but that "the clock is ticking."
The suicide bomber blew himself up next to a fuel tanker within half a kilometre of Iraqi President Jalal Talabani's home, in the mostly Shi'ite Karradah district where one of Wednesday's bombs exploded as well. Talabani, a Kurd, was not believed to have been the target.
The attack killed at least 12 people, including two Iraqi soldiers, wounded 34 people and set fire to the tanker, police said.
Britain's defence ministry also said two British soldiers died and three others were wounded by an explosion in southeastern Iraq. The attack occurred in Maysan province, a day after British troops transferred control of the area to Iraqi forces.
At least 3,314 members of the US military have died since the Iraq war started in March 2003, according to an Associated Press count. The figure includes seven military civilians. The British military has reported 144 deaths.