KYIV, Aug 12 — Ukraine has formally requested the extradition from Belarus of 28 alleged Russian mercenaries detained by security forces in Belarus, the Ukrainian prosecutor general’s office said on Wednesday.

Ukraine suspects the men of fighting with Russian-backed separatists in eastern Ukraine.

Belarus arrested the men last month and said they sought to destabilise the country prior to Sunday’s presidential election. Russia denies it uses mercenaries and has said the men were travelling through Belarus on their way to other countries. — Reuters