"As of 10 June, Russian forces around Sievierodonetsk have not made advances into the south of the city. Intense street to street fighting is ongoing and both sides are likely suffering high numbers of casualties," according to the UK MoD.

Read here Severodonetsk: fierce fighting continues

The UK MoD also says that Russia is resorting to inefficient weapon systems that risk “significant collateral damage and civilian casualties” because it is running short of more precise modern missiles:

Since April, Russian medium bombers have likely launched dozens of 1960s era Kh-22 (NATO designation, AS-4 KITCHEN) air-launched, heavy anti-ship missiles against land targets.

"These 5.5 tonne missiles were primarily designed to destroy aircraft carriers using a nuclear warhead," experts added.

When employed in a ground attack role with a conventional warhead they are highly inaccurate and can therefore cause significant collateral damage and civilian casualties. Russia is likely resorting to such inefficient weapon systems because it is running short of more precise modern missiles, while Ukrainian air defenses still deter its tactical aircraft from conducting strikes across much of the country.