KRAMATORSK: Russia claimed on Sunday to have captured the strategic Ukrainian city of Lysychansk and the entire frontline Lugansk region which would mark a decisive breakthrough for Moscow's forces seeking control of the country's east, reports AFP.

The development came as Belarus said it had intercepted missiles fired by Kyiv and Russia reported that Ukraine launched three cluster missiles at Belgorod, killing four people.

On Saturday, there were conflicting reports about Lysychansk's status with Ukraine denying Moscow's claim to have encircled the entire city, located across the river from neighbouring Severodonetsk which Russian forces seized last week.

Ukraine has yet to comment on the claim that Lysychansk has fallen following days of intense clashes.

"Sergei Shoigu has informed the commander in chief of the Russian armed forces, Vladimir Putin, of the liberation of the People's Republic of Lugansk," the defence ministry said in a statement quoted by Russian news agencies.

A few minutes prior to the announcement, which AFP has not verified, a spokesman for the Russian defence ministry had said fighting was ongoing in Lysychansk and that Ukrainian forces were "completely" surrounded. Russia's claim of a breakthrough came as Moscow said Sunday its anti-aircraft defences shot down three Tochka-U cluster missiles launched by "Ukrainian nationalists" against Belgorod, close to the Ukrainian border.

Belgorod governor Vyacheslav Gladkov said 11 residential buildings and 39 houses were damaged.