(Adds Klymenko reaction, background)
KIEV, May 3 (Reuters) - Ukraine's security service said on Saturday illegal military groups from Moldova's breakaway region of Transdniestria and Russian groups worked together to foment unrest in the southern port city of Odessa.
"The unrest, which occurred on May 2 in Odessa and led to clashes and many casualties, was due to foreign interference," a spokeswoman for the SBU security service told a news conference.
Kiev has long accused Russia of supporting uprisings in the south and east of Ukraine, and says pro-Russian forces in the Transdniestria region, just across the border, are helping their masters in Moscow to destabilise the situation.
Russia denies playing any role in Ukraine's uprising, saying Russian-speaking citizens are simply protecting their rights from a pro-Western government.
The security spokeswoman also accused former top officials, once part of ousted Ukrainian President Viktor Yanukovich's inner circle, of financing "saboteurs" to foment the unrest. She named Serhiy Arbuzov and Oleksander Klymenko.
Klymenko, former incomes minister and a close ally of Yanukovich, denied the allegation and called on Kiev to produce evidence. "I will tell you who is responsible: the blame for bloody Friday in Odessa lies entirely with the current government," he wrote on his Facebook page.
Arbuzov could not be immediately reached for comment. (Reporting by Natalia Zinets; Writing by Elizabeth Piper; Editing by Pravin Char)