Five Russian citizens are among eight people arrested for the bridge explosion that incensed Valdimir Putin and triggered his brutal missile bombardment of Ukraine.

The BBC reports three other suspects being held for the weekend blast on Russia’s only bridge to Crimea were Ukrainian and Armenian.

The arrests came as US President Joe Biden described Moscow’s wave of revenge attacks on civilians in Ukraine as “beyond the pale”.

In one of the latest strikes, at least seven people going about their day at a bustling marketplace were killed and injured in the annexed region of Donetsk.

The surprise hit took place in the eastern town of Avdiivka, which is under Ukraine control, and was during the busiest time of the day, said Donetsk regional military head Pavlo Kyrylenko.

A woman is helped across a destroyed bridge in Bakhmut, Donetsk. Photo: Getty

Russia has repeatedly blamed Ukraine for the embarrassing partial destruction of the Crimea bridge but Ukraine has refused to claim responsibility.

“At the moment, five citizens of Russia, three citizens of Ukraine and Armenia, who participated in the preparation of the crime, have been detained as part of a criminal case,” reported Russian news service RIA Novosti, based on a report by FSB and the Russian Investigative Committee.

“The explosive device was concealed in rolls with polyethylene construction film on 22 pallets with a total weight of 22,770 kilograms.”

‘Sociopath’s tantrum’

Both sides say the latest wave of Russian attacks has been on a huge scale, unseen at least since Russia’s initial wave of air strikes on the first night of the war in February.

The strikes – denounced in the West for deliberately hitting civilian targets – have been hailed by hawks in Moscow as a turning point that demonstrates Russia’s resolve in what it calls its “special military operation” in Ukraine.

But Western military analysts say the strikes came at a staggering cost, depleted a dwindling supply of long-range missiles, hit no major military targets and were unlikely to change the course of a war going badly for Moscow.

“Russia lacks the missiles to mount attacks of this sort often, as it is running out of stocks and the Ukrainians are claiming a high success rate in intercepting many of those already used,” wrote Lawrence Freedman, emeritus professor of war studies at King’s College London.

“This is not therefore a new war-winning strategy but a sociopath’s tantrum.”

Russian President Vladimir Putin’s latest strategy ‘won’t win the war’. Photo: Getty

Hawks in Russia had demanded for weeks that Mr Putin escalate the conflict, and many of them hailed Monday’s attacks.

Each Kalibr cruise missile is estimated to cost more than $10.35 million, meaning Moscow fired nearly $800 million worth of missiles on Monday alone.

Ukraine says Russia fired 83 cruise missiles on Monday and 28 on Tuesday, and that it shot down at least 43 of them on Monday and 20 on Tuesday. Moscow said on Monday it fired more than 70 and all its targets were hit.

Western military analysts have no firm figures for how many missiles Russia has left. But for months they have pointed to indicators suggesting supply is limited.

As far back as July, Joseph Dempsey and Douglas Barrie of the International Institute for Strategic Studies noted that Russia was increasingly using anti-ship missiles to strike targets on the ground.

This “suggests that Moscow is having to muster its remaining conventionally armed land attack cruise missile resources more carefully”, they wrote.

Russia still faces the same strategic difficulties it did before Monday’s attacks: Demoralised and poorly equipped forces spread along a 1000-kilometre frontline, with long supply lines vulnerable to Ukrainian attacks.

Ben Hodges, another former commander of US ground forces in Europe, said that despite Monday’s attacks, Ukraine still appeared to have “irreversible momentum” on the battlefield.

“Russia’s logistics system is exhausted and no Russian wants to fight in Putin’s war in Ukraine,” he tweeted.

-with AAP