DONETSK, July 22. /ITAR-TASS/. The Ukrainian troops have made further advances on east Ukraine’s Donetsk, self-defense fighters said on Tuesday.

The Ukrainian army started an offensive early on Tuesday from the settlements of Rubezhnoye, Sirotino and the Luhansk highway, the militia said.

The towns of Severodonetsk and Lisichansk were bombed by the Ukrainian military throughout the night. Shootouts in Severodonetsk are taking place in the center of the town, near the military commissariat, while tanks are shelling the town from the Rubezhnoye bridge, the self-defense fighters said.

Battles in Lisichansk are taking place near the Melnikov coalmine. A coke and chemical plant is under fire in a Donetsk suburb as a result of the city’s shelling by the Ukrainian army, the local news agency Novorossiya reported.

A shell fell on the territory of the Avdeyev coke and chemical plant on Monday evening, damaging communications, the agency said.

“Auxiliary workshops were stopped and coking products were ejected into the air,” the agency said.

Automatic gun shots are heard in Donetsk near the airport and the settlement of Oktyabrsky Rudnik. The night was disturbing for residents of several districts in the city where gunshots and explosions were periodically heard.

Residents of the city’s Kiev and Kuibyshev district still remain without electricity supplies. Power has been cut off at 28 transformer substations as a result of combat operations on Monday.

The Ukrainian army continues shelling the east Ukrainian city of Luhansk, especially its eastern portion, defenders of the Luhansk People’s Republic said.

Pro-Kiev troops and local militias in the southeastern Ukrainian Donetsk and Luhansk regions are involved in fierce clashes as the Ukrainian armed forces are conducting a military operation to regain control over the breakaway regions, which on May 11 proclaimed their independence at local referendums.

During the military operation, Kiev has used armored vehicles, heavy artillery and attack aviation. Many buildings have been destroyed and tens of thousands of people have had to flee Ukraine’s embattled south-east.