* Ukrainian interior, defence ministry troops in action
* After capturing separatist checkpoint, one unit withdraws
* Helicopters over city, stronghold of pro-Russian militants
(Adds separatist leader comment)
By Aleksandar Vasovic and Gleb Garanich
SLAVIANSK, Ukraine, April 24 Ukrainian forces
said they had killed several pro-Russian militants in clashes as
they closed in on the separatist-held city of Slaviansk on
Thursday, seizing rebel checkpoints and setting up roadblocks as
helicopters circled overhead.
Reuters journalists saw a Ukrainian detachment with five
armoured personnel carriers take over a checkpoint on a road
north of the city in late morning after it was abandoned by
separatists who set tyres alight to cover their retreat.
However, two hours later the troops pulled back. Local
militia moved in and began reinforcing the position with
sandbags. It was unclear why the military had withdrawn.
Earlier, the Ukrainian Interior Ministry said its forces and
troops from the Defence Ministry had killed "up to five
terrorists" while destroying three militant checkpoints
northeast of the centre.
A separatist spokeswoman in Slaviansk said early in the
morning that two fighters had been killed in a clash in the same
area, near a road leading to the town of Sviatogorsk.
Ukraine's government said it took back Sviatogorsk from
gunmen on Wednesday as it relaunched an "anti-terrorist"
operation to regain control of the Russian-speaking east.
It was unclear if Ukrainian troops were preparing to risk
storming Slaviansk, a city of 130,000 that has become the
military stronghold of a movement seeking annexation by Moscow
of the Russian-speaking, industrial regions of eastern Ukraine.
For the past few weeks, they have held back from combat,
saying they were concerned about civilian casualties - and about
provoking reprisals from Russia, which does not recognise the
new Ukrainian government and has warned that it would move to
protect Russian-speakers in the east, as it did in Crimea.
As the offensive at Slaviansk was confirmed, Russian
President Vladimir Putin said it would be a very serious crime
for Ukraine to use its army in the east and said there would be
The troops could be planning to impose a cordon around the
city to disrupt militants' contacts with the rest of the region
and to promote surrender negotiations that have been begun by
European OSCE monitors following an international accord signed
by Russia and Ukraine's Western allies a week ago in Geneva.
Slaviansk separatist mayor Vyacheslav Ponomaryov was quoted
by local online site slavgorod.com.ua saying: "If they break
into the city, we are ready for them." His men have machineguns,
grenade-launchers and at least one self-propelled artillery gun.
The soldiers seen taking the checkpoint near the village of
Khrestyshche had arrived from the direction of Sviatogorsk. They
appeared disciplined and well-armed, wearing camouflage with
black body armour and black helmets with riot visors.
To the south of Slaviansk, Reuters saw dozens of Ukrainian
airborne troops with armoured assault vehicles digging in in
mid-morning and manning a checkpoint on the main road to the
regional capital, Donetsk.
At Artemivsk, on the same road, the Defence Ministry said
troops repelled an overnight attack on their base by a group of
about 100 militants using machineguns and grenades. One soldier
was wounded, it added. The Interior Ministry said the raid was
led by Russian troops. Moscow denies having forces in Ukraine.
(Additional reporting by Alexander Reshetnikov in Slaviansk and
Alastair Macdonald in Kiev; Writing by Alastair Macdonald;
Editing by Philippa Fletcher)