Summary
Warplanes pounded ISIS's de facto Syrian capital Raqqa on Tuesday, killing at least 23 people including 13 militants, activists said.
The British-based Syrian Observatory for Human Rights said that either Syrian or Russian warplanes are believed to have carried out the strikes.
A U.S.-led coalition fighting ISIS has also bombed the city in the past.
The Observatory said at least seven ISIS fighters had been killed in clashes with the Syrian Democratic Forces and airstrikes by the U.S.-led coalition on Tuesday.
...