- US State Dept. cites "troubling increase" in civilian casualties since Russia began airstrikes
- Secretary of State John Kerry calls his Russian counterpart to express concern about deaths
- Russian Defense Ministry calls claims "without evidence"
(CNN)The U.S. sharpened its criticism of Russian airstrikes in Syria on Tuesday, charging that "indiscriminate attacks" had reportedly caused hundreds of civilian casualties and the displacement of over 100,000 residents.