In the holy city of Najaf, Qais al-Khazali, a spokesman for al-Sadr, said on Monday: "We call [on al-Sadr's followers] to ensure the security of Spanish troops until their departure as long as these forces do not perpetrate aggressions against the Iraqi people.
"Other countries which assign troops to the coalition in Iraq are urged to follow the example of Spain and to withdraw their forces to save the lives of their soldiers," he added.
A senior US-led occupation spokesman played down the impact of Spain's decision to pull its 1300 troops out of Iraq.
"The Spaniards have done a wonderful job," the spokesman said. "On the military point of view, it's not a large problem. We certainly have sufficient capabilities and we'll certainly have more countries coming."
"Spanish troops in Iraq will be withdrawn as soon as possible and with maximum security"
Jose Luis Rodriguez Zapatero,
Spanish prime minister
"Spanish troops in Iraq will be withdrawn as soon as possible and with maximum security," Spanish Prime Minister Jose Luis Rodriguez Zapatero said in a nationally televised broadcast on Sunday, a day after taking office.
Zapatero had originally said the withdrawal would go ahead unless there was a UN Security Council mandate for an international force in Iraq before the 30 June transfer of power to an interim government.
But Sunday, he said a UN resolution was unlikely to "match the content" of the Spanish demands for the continued presence of the troops.
For his part, US President George Bush told Zapatero he regrets Madrid's decision.
In a five-minute telephone call initiated by Zapatero, Bush "expressed his regret to president Zapatero about the decision to abruptly announce the pullout of Spanish troops from Iraq", said Whitehouse spokesman Scott McClellan.
"The president urged that the Spanish withdrawal take place in a coordinated manner that does not put at risk other coalition forces in Iraq," McClellan told reporters.
The president stressed the importance of carefully considering future actions to avoid giving false comfort to terrorists or enemies of freedom in Iraq," the spokesman said.
Al-Sadr also indicated through his spokesman that he favoured the deployment of a UN peacekeeping force in Iraq "on condition that it be made up of Muslim countries or countries which did not join the occupation of Iraq such as Russia, France or Germany".
Al-Sadr has asked for a UN Muslim
Khazali said the UN force must let the Iraqi people ensure their own protection by entrusting law and order duties to the Iraqi security forces, notably the police.
Until now, al-Sadr had rejected any role for the UN in Iraq, arguing that the world body was under the sway of occupation forces.
Bremer for his part warned: "If former members of the Republican Guards, the mukharabbat [ousted Iraqi leader Saddam Hussein's now disbanded intelligence service], the Fedayin Saddam and the Muqtada's militia are to be prevented from shooting their way into power, Iraqi security forces must have help until they are fully equipped and trained.
"This is what the coalition intends to do," he said in a statement issued by the occupation.
"But it is clear that Iraqi forces will not be able, on their own, to deal with these threats by 30 June when an Iraqi government assumes sovereignty.
Instead, Iraq and troops from many countries, including the United States will be partners in providing the security Iraqis need."
Violence continued on Monday as a mortar round hit the Swedish embassy grounds in Baghdad, causing no casualties, police said.
"The goal is to reach a global ceasefire and a return to normal in the city"
Iraqi Islamic Party
It was not clear whether the embassy was the target as the Iraqi agriculture ministry and an evangelical church are located nearby.
No Swedes were working at the embassy, located in central Baghdad, the Swedish foreign ministry in Stockholm said.
An upsurge in violence this month sparked by Sunni and Shia resistance fighters has left more than 90 US soldiers and hundreds of Iraqis dead.
In the flashpoint Sunni bastion of Falluja west of Baghdad, Iraqi mediators were to arrange another meeting between local civic leaders and occupation officials to consolidate an uneasy ceasefire in the city which has been under a US marine siege for two weeks.
"The goal is to reach a global ceasefire and a return to normal in the city," said Fuad Rawi, a leader of the Sunni Iraqi Islamic Party, which is involved in the mediation.
More than 600 Iraqis, half of them women, children and elderly people, have been killed in the fighting, according to hospital officials. But the US military says it is impossible to verify the figure.