There has been celebration on the streets of Iraq as US troops handed over full control of urban areas to local security forces.But far away from the smiles and pageantry, a bomb attack in the city of Kirkuk provided a deadly reminder of just how fragile the situation is. Many Iraqis fear the US pullout from towns and cities into rural bases will leave them less secure. But the government has declared June the 30th a public holiday: National Sovereignty Day. A full US withdrawal is on track for the end of 2011. Putting a cloud over the celebrations in Baghdad, a car bomb in the northern city of Kirkuk killed at least 25 people and left at least 40 others wounded. The bomb struck a busy market in a largely Kurdish part of the city. Iraq has also begun a tender process for the running of its oil and gas fields. This will enable foreign companies to get a foothold in the country for the first time in decades. Eight initial contracts went up for grabs, with promises that Iraq could hold some of the world’s largest untapped energy reserves. Among the deals today is a BP-led contract to develop the biggest oilfield in the south of the country.