(Adds Moscow rejecting Swiss diplomatic offer)

* Ukraine silent on how strike was carried out

* Satellite images show three craters, eight destroyed planes

* 'It's very good,' says ex-head of CIA

* Russian bombardment reported along frontline

By Tom Balmforth

KYIV, Aug 11 (Reuters) - Satellite pictures released on Thursday showed devastation at a Russian air base in Crimea, hit in an attack that suggested Kyiv may have obtained new long-range strike capability with potential to change the course of the war.

Pictures released by independent satellite firm Planet Labs showed three near-identical craters where buildings at Russia's Saki air base had been struck with apparent precision. The base, on the southwest coast of Crimea, had suffered extensive fire damage with the burnt-out husks of at least eight destroyed warplanes clearly visible.

Russia has denied aircraft were damaged and said explosions seen at the base on Tuesday were accidental.

Ukraine has not publicly claimed responsibility for the attack or said exactly how it was carried out.

"Officially, we are not confirming or denying anything; there are numerous scenarios for what might have happened... bearing in mind that there were several epicentres of explosions at exactly the same time," Ukrainian presidential adviser Mykhailo Podolyak told Reuters in a message.

Western military experts said the scale of the damage and the apparent precision of the strike suggested a powerful new capability with potentially important implications.

Russia, which annexed Crimea in 2014, uses the peninsula as the base for its Black Sea fleet and as the main supply route for its invasion forces occupying southern Ukraine, where Kyiv is planning a counter-offensive in coming weeks.

"I'm not an intel analyst, but it doesn't look good," Mark Hertling, a former commander of U.S. ground forces in Europe, wrote on Twitter, linking to an image of the devastation at the Russian base.