UKRAINE claims it has recaptured part of key territory in Donbas region with Russian troops suffering from exhaustion and low morale.

Just days after announcing Ukrainian fighters would withdraw from Severodonetsk, the regional governor said they had succeeded in taking back a part of the city which had been 70% occupied.

Serhiy Haidai added that delivery of new artillery from the US would be enough to make the Russian infantry “run away”.

Meanwhile the government in Estonia has collapsed, fuelling fears that Russia is attempting to destabilise the country which is host to a key Nato deployment of UK troops. Prime Minister Kaja Kallas of the liberal Reform party, accused her coalition partners, the Centre Party, of “actively working against Estonia’s core values” in the face of the threat to security. The Centre Party has historic ties with Russian President Vladimir Putin’s United Party, although it claimed to have severed them after the invasion of Ukraine.

As the conflict passed its 100th day, Ukrainian president Volodymyr Zelenskyy mocked Russia’s military, saying it had once been thought of as “the second army of the world” but all that was left was “only a bitter smile … war crimes, disgrace and hatred”.

However, Russia is increasing air strikes in the eastern Donbas region, according to the UK’s Ministry of Defence (MoD), and Russia claims to have shot down a Ukrainian military transport plane carrying munitions near the Black Sea port of Odesa and blasted an artillery training centre in the Sunny region where foreign instructors were training Ukrainian forces.

Four foreign military volunteers from Germany, Australia, the Netherlands and France have also been killed according to the International Legion of Defence of Ukraine but it is not known yet where or how they died.

The 500-year-old All Saints’ Hermitage Cathedral in Svyatohirsk was yesterday in flames after being hit by a Russian missile. Located in a predominantly Russian speaking area, it is overseen by the Moscow Patriarchate.

Ukraine is counting on missile systems from the UK and the US to gain the upper hand but Russia’s Defence Minister Sergei Shoigu has made clear Russia’s aim is to “accelerate” its offensive.

Meanwhile hundreds of people are fleeing Sloviansk in the east of Ukraine, with numbers almost doubling in recent days, according to the head of the city’s military administration. Vadym Lyakh said a missile strike that killed three people on Tuesday had sparked a greater exodus, with hundreds fleeing daily. Russian forces are understood to be bolstering their units near the city as they gear up for a renewed assault.

The UK’s MoD said the increased use of unguided munitions has led to the widespread destruction of built-up areas in Donbas and has almost certainly caused substantial collateral damage and civilian casualties. It added that Russia’s number of precision guided missiles “are likely to have been significantly depleted”.

The MoD expects Russia to win control of the whole of the Luhansk region in the east of Ukraine within a fortnight, after Moscow changed strategy to focus on the Donbas region after failing to take Kyiv.

The MoD update came a day after Zelenskyy said 20% of Ukraine was now under Russian control, with Donbas “almost entirely destroyed”. He said this amounted to almost 125,000 square kilometres.

Sea creatures are another casualty of the war with injured and dead dolphins washing up on the Black Sea coast after being killed or hurt by powerful military sonars.

Renewed attempts to stress the need for a negotiated settlement of the conflict are being made by the US and its allies with European and US officials meeting regularly in recent weeks to discuss a possible framework for a ceasefire but Ukraine has said there is no point in negotiations until Russian forces are pushed back to their own borders as far as possible.

US President Joe Biden said that there would have to be a “settlement” between Russia and Ukraine at some point but “what that entails, I don’t know”.

Meanwhile concern is growing over the millions of tons of Ukrainian grain stuck in silos in the south of the country, amid allegations that Russian ships are staging a blockade on Black Sea ports. Russian President Vladimir Putin has denied Moscow is preventing its export, blaming the West for rocketing global food prices.

The European Council has now formally adopted its sixth package of sanctions against Moscow but Zelenskyy has said they are “too little, too late”.