BAGHDAD: Iraqi security forces jubilantly paraded in tanks and armored vehicles yesterday as they took control of towns and cities, but the celebrations were marred by a car bomb that killed 30 people. Iraq marked the June 30 pullback of US troops with a national holiday six years after the invasion that toppled Saddam Hussein but sparked an insurgency and sectarian bloodshed that left tens of thousands dead.

American troops quit their posts in built-up areas by midnight, ahead of a complete pullout by the end of 2011.

Before a car bomb in the northern oil hub Kirkuk overshadowed the festivities, Prime Minister Nuri Al-Maliki took issue with critics of Iraq’s Army and police, insisting they were up to the task of defending the country in the wake of the US withdrawal.

“It is an offense to the Iraqis. The people who said that the foreign troops would never withdraw and would keep permanent bases in our country were giving a green light to the terrorists to kill civilians,” he said.

White House spokesman Robert Gibbs described the US pullback as an “important step forward” but added that the remaining US forces in Iraq would remain “vigilant.”

At least 30 people, including women and children, were killed and 80 wounded in the early evening attack in Kirkuk, according to the city’s director of health. The blast tore through a busy market in a largely Kurdish part of the city, which is seen as a potential flashpoint between ethnic Kurds, Arabs and Turkomen. Police said the death toll could rise.

Al-Maliki, who laid a wreath at Iraq’s tomb of the unknown soldier inside the heavily fortified Green Zone, wanted the pullback date to coincide with the outbreak in 1920 of a revolt against British occupation after World War I.

President Jalal Talabani thanked US forces for their role in overthrowing Saddam’s regime in 2003, and in the years of bloodshed that followed. “They bore the burden and dangers against the most cruel regime and against the mutual enemy — the terror,” Talabani said on state television.

The handover coincided with a US Army announcement that four of its soldiers died from combat-related injuries on Monday.

Gen. Ray Odierno, the top US commander in Iraq, told reporters he believed Iraq was now a better country. “I believe the Iraqi people are much better off not having a dictator such as Saddam Hussein,” he said. “They are now going to be able to see that they can move ahead and the people of Iraq will have a say in their government.” Odierno, however, refused to give a number for how many US troops would be left in urban centers. “The reason I won’t do it is because it will be different every single day,” he told US journalists in a video briefing from Iraq.