Pro-Russian rebels down Ukraine army helicopters

Pro-Russian rebels have shot down two of Ukraine's army helicopters during an "anti-terror" operation in the eastern city of Sloviansk, Kiev says. Ukraine's military said a pilot and serviceman were killed and nine rebel checkpoints seized. However, separatists at three Sloviansk checkpoints told the BBC they were still in control there.
Background:
Ukraine crisis: Sloviansk rebels down army helicopters [BBC]
Rebels down Ukraine helicopters, Putin denounces city assault [Reuters]