The United Nations mission to Iraq says that at least 659 Iraqis have been killed during violence in November, a drop by almost a third compared to the group's figures for last month.

The U.N. figures issued Sunday showed that 565 civilians and 94 security personnel were killed in November, compared to 979 reported killed in October. The UNAMI statement said it may undercount the actual total.

Yet, U.N. mission chief Nickolay Mladenov expressed concern over the recent uptick in "execution-style" killings.

Last week, Iraqi police found a total of 31 bodies in three separate places around Baghdad, recalling the height of sectarian violence in 2006-2007 when insurgents and militias abducted and killed members of other religious groups.