The presence of Russian citizens in Ukraine’s south-east does not mean Russia’s military presence in the country, Kremlin spokesman Dmitry Peskov said on Friday.

"There [in Ukraine] may be citizens of all the countries: both Ukraine and Russia, and may be citizens of European countries," Peskov told reporters. "But there are no Russian Armed Forces there, about what our colleagues in Ukraine and our colleagues in Europe and Washington have been speaking all the time," he said.

The Russian presidential spokesman commented on the reports about the recent detention of another Russian citizen in Ukraine. He stressed that this information needs to be checked and confirmed.

Ukrainian President Petro Poroshenko told reporters earlier in the day that 12 militias, including one Russian citizen, were detained during the fighting near the town of Maryinka, near Donetsk.

On Wednesday, the standoff escalated on the contact line, near Maryinka in the vicinity of Donetsk, where active combat actions were seen between the Ukrainian forces and militias.

The Donetsk republic’s defence ministry spokesman Eduard Basurin has called the events a "large-scale provocation of Ukraine’s forces."

Last month, Russian nationals Alexander Alexandrov and Yevgeny Yerofeyev were detained by Ukraine’s SBU in the Lugansk region. The Ukrainian authorities claimed that the persons were allegedly Russian servicemen.

The Russian Defence Ministry later stressed that the Russian citizens were not active servicemen of the country’s armed forces at the moment when they were detained.

The leader of the Luhansk People’s Republic, Igor Plotnitsky, said that Alexandrov and Yerofeyev were members of the LPR’s people’s militias adding that their names were the first ones on the list for the prisoner swap. He noted that Kiev could use the detention for provocations.