Troops from Kyiv were reported to be launching a simultaneous offensive in several locations against rebels in eastern Ukraine on Tuesday.
Russian news agency Interfax said there had been clashes near Donetsk, Luhansk, Horlivka, Pervomaisk and Llovaisk.
Government forces say they are preparing for the final stage of recapturing the city of Donetsk. They claim to have cut off Donetsk from the other main rebel-held city, Luhansk.
At least 1,500 people have died since Ukraine’s new government sent in troops to put down an uprising by separatists in April. Another 4000 have been wounded.
At the same time, fighting has displaced hundreds of thousands of people, many of whom have fled to Russia for safety.
Ukraine’s parliament will vote on Tuesday afternoon on a possible new round of sanctions against Russia.
It includes a list of 172 Russian citizens and 65 companies and could include state-owned gas giant Gazprom which currently provides gas to Europe via pipes running through Ukraine.
The move could lead to a disruption in gas supplies to Europe.