Baghdad: The much-vaunted newsecurity plan for Iraqwas officially launched by Prime Minister Nuri al-Maliki Wednesday amidcontinuing civilian deaths in insurgent attacks and major anti-militantoperations by US and Iraqi forces.

Speaking during a visit to Karbala,100 km south of Baghdad,al-Maliki said the new security plan offered Iraqis a vital chance for 'building their homeland'.

"The launch of the security plan is a message to allthose who rebelled against the law," he said, adding that the plan wasapplicable to all Iraqi religious and ethnic communities without exceptions.

The new security initiative had been informally in effectsince Feb 6 with operations carried out by Iraqi troops backed by multinationalforces in Baghdadand nearby cities.

Earlier Wednesday, the so-called Mahdi army, a Shiite Muslimmilitia in Iraq, insistedthat its leader, Moqtada al-Sadr, remains at his headquarters in the Shiiteholy city of Najaf in southern Iraq.

 Press reports said Tuesday that al-Sadr, son of a Shiitecleric slain in 1999 under the former Iraqi regime, had crossed from Iraq intoneighbouring Iran two to three weeks ago. US General William Caldwell confirmedin an interview Wednesday with CNN that the United States believes al-Sadr was in Iranbut declined to say why the anti-American preacher might have left Iraq.

The militantly anti-American al-Sadr is linked to a bloc inthe new Iraqi parliament.

"The al-Sadr movement strongly supports the Iraqigovernment's new security plan," said former parliament member Fattahal-Sheikh, a high-ranking member of the Mahdi army, which is active in Baghdad and southern Iraq.

In Tehran, Iranian state newsagency IRNA quoted an unnamed official source as denying press reports thatal-Sadr was in Iran.

An Iraqi government source said Wednesday that moves werebegun by authorities to close Iraq'sborders with Syria and Iran,as part of the plan.

"Meanwhile, a joint Iraqi and USmilitary force stormed a Shiite mosque in northern Baghdad. During the raid on the Brathamosque, money, weapons, computers and mobile phones were seized," witnessessaid.

Parliament member Jalal al-Din al-Saghir is the imam of themosque, one of the oldest Shiite mosques in Baghdad.

Despite the new security measures, three Iraqis were killedand five injured in a pair of bombings Wednesday.

A roadside car bomb killed two Iraqis and wounded three insouth-eastern Baghdad.Iraqi police sealed off the blast area as ambulances rushed to the scene.

In Basra, 550 km south of Baghdad, an explosivedevice implanted on a main road was detonated as a British Army patrol passedthe site, witnesses said. One Iraqi was killed in the blast, but no Britishmilitary casualties were reported.

Witnesses said that a British base in the suburbs of Basra came under rocketfire, but no official confirmation was available.

Elsewhere in Iraq,US-led coalition forces on Wednesday detained 27 terrorist suspects, the US militaryreported.

During a series of raids in Ramadi, coalition forcesdetained 20 suspected terrorists with alleged ties to al-Qaeda in Iraqand seized computers as well as electronic equipment.

In Baghdad,coalition forces detained another four suspected terrorists and three more inKarmah.

Separately, US-led coalition forces killed 15 suspectedterrorists and prevented two improvised explosive devices from being placedWednesday morning in Baghdad'sArab Jabour district during operations targeting al-Qaeda terrorists and anassociated improvised explosive device network.