An explosion in the vicinity of a strategic oil pipeline network linking north and south Iraq on Thursday sent flames and smoke into the air, a witness said.
It was not clear what caused the blast near the town of Musayyib, around 90 km (60 miles) south of Baghdad, or whether the strategic pipeline itself was damaged.
Saboteurs operating in the north have been trying to expand their operations south of Baghdad and earlier this year attacked the north-south pipeline, which was already in need of major repairs after years of neglect and post-war looting.
Iraq plans to pump crude from the Kirkuk oilfields through the pipeline to Gulf terminals as an alternative to the northern export route, which has been plagued by sabotage.