The detention of 33 Russian citizens in Belarus was the result of a joint operation by Ukrainian and U.S. security services, Russian President Vladimir Putin said.

"It's clear now that this was an operation of the security services. The people you mentioned were used blindly and moved to Belarusian territory for a completely legal purpose. They were told they would go to third countries, such as Latin America and the Middle East, to do a completely legal job," Putin said in an interview with the All-Russia State Television and Radio Broadcasting Company.

"But, in fact, they were dragged into Belarusian territory and presented as a possible attack force that could be used to destabilize the situation during the election campaign," he said.

"That was absolutely untrue," Putin said.

"Once again, those people were on their way to work in a third country. They were simply lured there, dragged across the border. Our border guards didn't let them go, by the way; they couldn't leave," Putin said.

He also said that the men were traveling using fake documents.

"It was an operation staged by the Ukrainian security services together with the American ones. We know that for sure now," Putin said.