BAGHDAD - An explosion on a bridge in Baghdad on Thursday killed at least six people and sent several cars plunging into the Tigris River below, Iraqi police said.
Police said the blast, which occurred during the morning rush hour, had damaged the Sarafiya bridge in northern Baghdad. One of its girders had collapsed.
Four or five cars had fallen into the river and the death toll could rise, police added.
Iraqiya state television said a number of people had been killed and wounded.
The Tigris River cuts Baghdad in half and the Sarafiya bridge is a key artery in the northern part of the city.
US and Iraqi forces launched a security crackdown in the capital two months ago that has managed to reduce death squad killings, but car bombs have remained a problem.
Checkpoints are placed at the entrances to most of the many bridges that cross the Tigris in Baghdad.
The security operation in Baghdad is seen as a last ditch attempt to halt Iraq's slide into sectarian civil war.
The US military said on Wednesday that for the third month in a row, civilian casualties had declined in Baghdad but that in the same period there had been an increase in casualties across Iraq.