KIEV, Aug 6 (Reuters) - Eighteen Ukrainian servicemen have been killed and 54 injured in fresh fighting with separatist rebels, a military spokesman said on Wednesday.
The spokesman, Andriy Lysenko, said government forces had clashed with separatists 25 times in parts of eastern Ukraine near the Russian border in the 24 hours up to Wednesday morning as they continued to squeeze rebel positions.
Ukrainian forces, he said, had again been shelled from inside Russian territory while Ukrainian frontier guards near the border town of Luhansk had come under a four-hour mortar and artillery attack.
"In the past 24 hours 18 service personnel have been killed in battle and 54 have been wounded," he told journalists, saying casualties had been sustained in several different incidents in the east.
Government troops have been battling the rebels since April in the Russian-speaking east in a conflict which the United Nations High Commissioner for Human Rights says has cost the lives of more than 1,100 people, including government forces, rebels and civilians.
The new overnight deaths among government forces suggests that Kiev military losses now total around 400.
Ukraine and its Western allies accuse Russia of orchestrating the revolt and arming the rebels - something denied by Moscow. The United States and the European Union have imposed sanctions on Russia.
Fighting has intensified since the shooting down of a Malaysian airliner last month, killing all 298 people on board - an act the West laid at the door of the rebels. Russia and the rebels blame the disaster on Kiev's military offensive.
Residents in Donetsk, east Ukraine's main industrial hub and now the main redoubt of the rebels, said Ukrainian warplanes had carried out air strikes overnight.
One resident, who gave only her first name of Svetlana, said: "It was terrible. It was the most powerful strike we have had. The walls of the apartment shook when it (the missile) struck the market and the bus stop next to it".
Lysenko, questioned over the reports, denied that Ukrainian planes had carried out air strikes on the town of nearly one million and said the only Ukrainian plane near the town had been an aircraft providing communications support for troops on the ground.
"The Ukrainian military does not bomb the towns of Donetsk and Luhansk or any other similar populated places," he said.
(Reporting by Natalya Zinets in Kiev and Maria Tsvetkova and Lina Kushch in Donetsk; Writing by Richard Balmforth)