By Ahmed Rasheed
BAGHDAD (Reuters) - Prime Minister Nuri al-Maliki declared a new dawn on Saturday as Iraq celebrated the departure of American troops at a ceremony held amid tight security and without Maliki's key political rivals.
Iraq was engulfed in its worst political crisis in a year after the last U.S. troops left on December 18 when Maliki sought the arrest of Sunni Vice President Tareq al-Hashemi, threatening a frail coalition government of Sunnis, Shi'ites and Kurds.
Saturday marked the end of the 2008 security pact agreed by then-President George W. Bush and was the last day for U.S. troops to withdraw from Iraq, nearly nine years after the invasion that toppled Sunni dictator Saddam Hussein and allowed the Shi'ite majority to take power.
Except for a small military contingent attached to the U.S. embassy in Baghdad, the last of the American troops departed nearly two weeks ago.
"I declare this day, the 31st of December, on which the withdrawal of foreign forces from Iraq is complete, as a national day," said Maliki in a televised ceremony, surrounded by security officials in dress uniforms.
"It is Iraq's day. It is a feast for all Iraqis. It is the dawn of a new day in Mesopotamia ... Your country is free."
Maliki said he would work to maintain freedom and "respect political, intellectual and religious diversity."
Earlier, thousands of Iraqis received a text message on their phones bearing the name "AL-MALIKI" in bold letters.
"All of us for Iraq ... Glory is for the people," the message said. "I congratulate you and our proud Iraqi people on this great day in history ... My love and respect to you and your families. Your brother Nuri al-Maliki."
Hundreds of people attended the ceremony in a Baghdad sports arena usually used for basketball and volleyball, but there was no sign of Iyad Allawi, the head of the cross-sectarian Iraqiya political bloc, Osama al-Nujaifi, the Sunni speaker of parliament or other Sunni lawmakers and rivals.
The venue was surrounded by hundreds of soldiers and police. Army helicopters hovered overhead, snipers occupied positions on nearby buildings and explosives-sniffing dogs checked attendees.
Maliki's move against Hashemi, accused of running death squads, and his request to parliament to remove Deputy Prime Minister Saleh al-Mutlaq, another prominent Sunni, stirred fears of another wave of sectarian violence in Iraq.
Sunni-supported Iraqiya announced a boycott of parliament and Maliki warned he could form a majority government.
Maliki did not mention the current political crisis or Hashemi by name, but said: "After today, there will be no place for those who put one foot in the political process and the other with the terrorist organizations."
Iraq's Sunnis, who held power for decades under Saddam, have felt marginalized in politics since his overthrow in 2003. The inclusion of Iraqiya in a "unity" government following months of negotiations last year was considered a key to avoiding a slide back into sectarian conflict.
The ceremony, held on a Saturday when Iraqis are normally off work, did not appear to prompt any large-scale celebrations.
In Babil province, south of the capital, an Iraqi flag was raised to the top of a 24-metre pole in a ceremony attended by Governor Mohammed al-Masoudi and about 500 guests.
Soldiers and police paraded with banners, one reading "Sovereignty day, a day of dignity for all Iraqis."
Iraqi forces held a military parade at the Habaniya base in western Anbar province, where Lieutenant General Abdul-Aziz al-Ubaidi said: "The armed forces are ready to protect our homeland, its waters, its land and its sky."
Earlier on Saturday gunmen killed five members of the government-backed Sunni Sahwa militia at a security checkpoint in the town of Khan Bani Saad, about 30 km (20 miles) northeast of Baghdad in restive Diyala province, an al Qaeda stronghold.
It was the second major attack on the Sahwa, a frequent al Qaeda target, in a day. A Sahwa member and three bodyguards were killed by a sticky bomb on Friday in the town of Taji.
(Additional reporting by Mohammed Ameer; Writing by Jim Loney; Editing by Tim Pearce)