A Russian court Wednesday ruled to detain two Colombians suspected of acting as mercenaries, a crime under Russian law, after they reportedly fought in Ukraine.

The Moscow courts' press service said that the men, named as Jose Aron Medina and Alexander Ante, had been remanded in custody by Lefortovsky district court at the request of investigators.

The court ruled to keep them in preliminary detention until October 22.

They are suspected of acting as mercenaries in an armed conflict, punishable by up to 15 years in prison, the court said.

Russia's SOTA media outlet reported, citing Colombia's El Tiempo newspaper, that the two men had been fighting on the side of Ukraine and may have been detained while heading home via Venezuela.

It was not immediately clear how the men had arrived in Russia, but Venezuela has close ties with Moscow.