The bodies were found Saturday during a joint operation with U.S. forces, the military said in a statement.
Last month, Iraqi police reported finding 25 bullet-riddled bodies, some decapitated, in a mass grave in Nadhum village, close to Lake Tharthar. At the time, police said it appeared the victims had died within the past three months.
But an Anbar provincial police official, Col. Jubair Rashid Naief, said Tuesday that he believed these were not the same bodies, and that this was a second mass grave found in the area in less than a month.
Naief said the bodies were found in a drainage canal, and that some of the victims were wearing heavy clothes - indicating they may have been killed last winter.
After the discovery, U.S. and Iraqi forces launched an operation Sunday, including ground raids and air assaults targeting al-Qaida in the area, the U.S. statement said.
About 30 suspects were detained, it said. Two car bomb facilities and a number of weapons caches were also found, it added.
Iraqi officials are investigating the mass grave, trying to identify the bodies and notify families. The statement did not say how long the victims were believed to have been dead.
Putin's official spokesman Dmitry Peskov commented on remarks in the US media about failures in launching nuclear-capable missiles in Russia
The Buk system that shot down MH17 belonged to the 53rd SAM missile brigade of the Russian Ministry of Defense, investigators say after looking at a few pictures on the net
It has long been understood that the West has been trying to subject Russian borders to total control. We have not seen such activity even during the Cold War