The Islamic State has lost 45 percent of the territory it once held in Iraq and 20 percent of areas it controlled in Syria, according to new estimates by a U.S.-led coalition combating the extremist group.

Those slow but steady battlefield losses in Iraq are prompting the Islamic State to strike back against civilians with terrorist bombings, the latest killing dozens in Baghdad on Tuesday.

The territory seized by Iraqi forces, aided by coalition airstrikes and advisers, is up from 40 percent announced earlier this year, according to the latest estimates. The percentages are based on areas the militants controlled at their peak strength after they swept into Iraq in 2014. […]