Airs strike against extremists in Syria and Iraq grow, as the US-led coalition now includes Britain, Denmark and Belgium.
European countries are taking part only in the Iraq part of the military campaign, leaving the Syria operation to US and five Arab allies who began conducting airstrikes on Tuesday.
U.S.-led strikes pressure al Qaeda's Syria group to join with Islamic State http://reut.rs/ZW11gK via @reuters
BBC News - MPs support UK air strikes against IS in Iraq http://www.bbc.com/news/uk-politics-29385123
Islamic State tightens siege of Syria town, more Europeans join alliance http://reut.rs/1pwiDot via @reuters
News Wrap: UK joins airstrikes on Islamic State in Iraq, not Syria http://to.pbs.org/1rr44bf via @NewsHour