BAGHDAD, Iraq (CNN) -- The number of Iraqi civilian deaths in January dropped to the lowest monthly levels since the U.S.-led invasion began in 2003, according to government numbers supplied to CNN.
In January, 138 civilians were killed in violence across the country, compared with 238 in December, according to the figures, based on data collected by Iraq's Health, Defense and Interior ministries.
Also this month, 303 civilians were wounded, nearly half of the 601 wounded in December, according to the numbers.
Casualty figures have been steadily dropping since fall 2007. The U.S. military attributes the decline to several factors: the U.S.-led "troop surge"; the growth of the Sunni militant movement to back the United States, called Awakening Councils; and Shiite cleric Muqtada al-Sadr's call for his militia to cease fire.
About two dozen Iraqi police officers were killed in January, compared with 58 in December.
In addition, about 15 U.S. troops have been killed in January in Iraq, roughly half the number of those killed the previous month.
Despite the decline in civilian and other casualties, the death toll for Iraqi soldiers increased in January, from 18 in December to 27 this month.
CNN's Jomana Karadsheh contributed to this report.