Artillery fire, airstrikes and ground forces.
According to Sergei Gaidai, Ukraine's governor of Luhansk, significant Russian forces have gathered to crush the resistance in the already heavily war-torn city of Sieverodonetsk.
Only a small part of the city, where the lack of clean water has grown into a major problem, is still controlled by Ukraine.
According to several international observers, including the Washington-based think tank Institute for the Study of War, the city risks falling within a few weeks.
Remaining under the chemical factory
Of Sieverodonetsk's 100,000 inhabitants, only a fraction will remain in the city.
Up to 500 people, civilians and soldiers, are still to hide in the bunkers under the surrounded chemical plant Azot.
According to Ukrainian authorities, a large number of Russian soldiers are tied up around the site.
No major evacuation has yet taken place.
Ukrainians say they do not trust the Russians' repeated promises of a humanitarian corridor.
Numerical advantage
Fighting is going on at the same time in all parts of the region.
According to Governor Sergey Gaidai, control of the suburb of Metolkine was lost over the weekend.
The Russian forces have also recently achieved success in Toshkivka, a town south of Sieverodonetsk.
The Ukrainian army is holding out, but more than 90 percent of the Luhansk region is currently under their control, writes Reuters.
They are now said to be fighting not to be completely surrounded.
According to Hanna Maliar, Ukraine's deputy defense minister, Russia aims to take over the entire region before the end of the week.
"The enemy has the upper hand both numerically and in terms of weapons, so the situation is very difficult.
At this moment, decisive battles are underway with maximum intensity, says Hanna Maliar, according to Reuters.