Ukraine's snap parliamentary election was mostly fair, the leading group of Western observers said yesterday.

"At this crucial moment for the future of their country, Ukraine's institutions and voters responded to daunting challenges with an election that largely upheld democratic commitments," said Kent Harstedt, head of the OSCE observer mission.

"That response and, in particular, the authorities' determination to enable voting in as many areas of the country as possible, demonstrate a resilience that will help the country overcome its national and international challenges," Harstedt, from the Organisation for Security and Cooperation in Europe, said at a press conference.

Andrej Plenkovic, head of the European Parliament delegation in the observer mission, said Ukrainians had "chosen Europe and peace".

Results with 40 percent of precincts reporting showed Prime Minister Arseniy Yatsenyuk's People's Front and the party of President Petro Poroshenko neck and neck with about 22 percent of votes each.

Russia's deputy foreign minister said yesterday parties backing a peace process to end the conflict with pro-Russian rebels in east Ukraine won a clear victory at Sunday's parliamentary polls.

"It is already clear that parties which support a peaceful resolution of the internal Ukrainian crisis received a majority," Grigory Karasin was quoted as saying by state-run Ria Novosti news agency.