BAGHDAD -- Iraq's prime minister said Saturday that the full withdrawal of U.S. combat troops from cities and towns was a message that his country was ready to take over its own security, even as he appealed for national unity after a week of attacks left more than 250 people dead.
Both of Iraq's vice-presidents joined in the call, with one of them warning Iraqis to stay away from crowded places favored by bombers.
There have been concerns that Iraqi forces will not be able to provide adequate security after U.S. combat troops completely pull out of Baghdad and other urban areas by June 30, part of a security agreement that calls for all American troops to leave Iraq by the end of 2011. Under the agreement, which took effect Jan. 1, U.S. troops have taken a secondary role, giving Iraqi forces the lead in operations.
On Saturday, few if any of the 133,000 U.S. troops still in Iraq were visible in its cities, with most already having pulled out of urban centers in recent weeks. They have assembled in large bases outside urban centers and will continue to conduct combat operations in rural areas and near the border.
"We are on the threshold of a new phase that will bolster Iraq's sovereignty," Prime Minister Nouri al-Maliki said at a memorial service for a Shiite leader who died six years ago. He added that June 30 was "a message to the world that we are now able to safeguard our security and administer our internal affairs."
Police said they had bolstered checkpoints and patrols, especially in Shiite areas of Baghdad where bombers have targeted markets with deadly effect.
Nearly all the bombings that began on June 20 have been in Shiite areas, including the two deadliest attacks. They were a June 20 bombing that killed 82 people outside a mosque in northern Iraq, and another on June 24 in the Shiite enclave of Sadr City that killed 78.
Al-Maliki blamed the bombings on the remnants of al-Qaida in Iraq and said they were aimed at restarting violence between Shiites and Sunnis.
"Today we are in need of unity, as they have shown their teeth against us," al-Maliki said of the extremists responsible for the attacks. "Our system falls when we return to sectarianism."
Iraq nearly slipped into civil war in 2006 and 2007, and tens of thousands of people died in attacks between Sunni extremists such as al-Qaida and Shiite militias and death squads. It was brought back from the brink by a huge inflow of U.S. troops in 2007 in what became known as the "surge."
As part of an apparent effort to deflate sectarian tensions, the United States late Friday released its most important Shiite prisoner, a key aide to anti-American cleric Muqtada al-Sadr. Shiites have been complaining that hundreds of prisoners, many of them militiamen and followers of al-Sadr remain behind bars.
Abdul-Hadi al-Daraji, one of al-Sadr's closest political advisers, was arrested in January 2007 at a mosque in Baghdad's eastern Shiite district of Baladiyat. He was handed over by U.S. forces to Sami al-Askari, a senior aide to al-Maliki, inside Baghdad's Green Zone and immediately released.
Vice President Tariq al-Hashemi, a Sunni, called in a statement posted on his Web site for "our people to be more cautious and avoid, whenever possible, crowded areas unless there is something important." He also called on Iraqi security forces to beef up their presence in public areas, markets and mosques.
U.S. and Iraqi officials have warned of a possible spike in violence over the next week.
Police and army units have been beefed up around Baghdad, especially around Sadr City, and furloughs for all security services have been canceled ahead of June 30, which has been declared a national holiday by al-Maliki's government.
The date has been declared "Victory Day" by al-Maliki, and Iraq's ability to provide security for its people without American troops has evolved into the cornerstone of his administration as he prepares for next January's elections.