BAGHDAD  Attackers wearing military uniforms tried to storm the Central Bank of Iraq on Sunday, setting off explosions and engaging in gun battles with the police and soldiers that lasted hours during the afternoon rush and paralyzed parts of the capital. At least 15 people were killed and 50 were wounded, officials said.

The bedlam in the crowded neighborhood, filled with banks, markets and shops, came a day before Iraq’s new Parliament was to convene, underscoring the deep sense of uncertainty here over when a new government will be formed after months of deadlock. The scene itself was reminiscent of the strife that the country experienced during the worst sectarian bloodshed in 2006 and 2007, when Iraq teetered on the edge of anarchy.

In the pandemonium, bystanders, employees and shoppers ran for cover. Witnesses said many were killed or wounded in the crossfire between attackers and the police. For hours, ambulances ferried the wounded from the neighborhood.

“A disaster  the scene was terrifying,” a shop owner, Raji Mohammed, said. “I didn’t know whether they were roadside bombs, mortars, suicide bombers or car bombs.”