Ukrainian government troops over the past 24 hours heavily bombarded two key rebel cities under siege in eastern Ukraine, Gorlovka and Donetsk, killing 44 civilians and forcing government offices to be evacuated.
Seventeen civilians, including three children, were killed and 43 others were injured in artillery fire in Gorlovka, Efe news agency reported citing the town council.
The Ukrainian military leadership announced that its forces were besieging the city, which had 250,000 inhabitants before fighting broke out earlier this year with pro-Russian separatists controlling the area.
Gorlovka is only 20 km away from the city of Donetsk, the stronghold of the militias, where a downtown government building was evacuated Tuesday due to intense artillery fire, including the offices of the leader of the self-proclaimed Donetsk People's Republic, Alexandr Borodai.
"Two shells fell on residential buildings," killing one person and wounding three others, and several hit targets near Vishnesvski hospital, said the press office of the separatists, cited by the Russian news agency Interfax.
A curfew is in force in Donetsk, from where tens of thousands of people have fled in the last weeks.
Ten Ukrainian troopers were also killed in the past 24 hours in fighting with the rebels, and more than 50 were wounded.
Government troops have intensified their offensive on rebel positions in the last days in an attempt to open a secure corridor for international investigators trying to reach the site of the July 17 crash of a Malaysia Airlines passenger plane with 298 people on board which was believed to have been downed by the rebels.
Once the area is secured, the Netherlands and Australia, the two countries which had the largest number of passengers on board flight MH17, will deploy a police mission to protect the experts.
Meanwhile a Xinhua report said that in Gorlovka's neighbouring town of Yasynovata, at least four people were killed and seven others wounded in an air strike on an apartment building.
Heavy fighting and machine gun fire have been also reported in the Lugansk region. According to Lugansk city council's press service, at least five civilians were killed in a fierce battle for control of the city over the past 24 hours.
Ukrainian forces have been fighting with insurgents since mid-April to regain control over the seized cities and towns in eastern part of the country.
According to the UN, the toll in the clashes has reached at least 1,129, while around 3,442 others have been wounded.
Ukraine said it had lost 325 of its troops and 27 border guards in the conflict.
