Ukrainian President Volodymyr Zelenskiy asked his Belarusian counterpart Alexander Lukashenko on Wednesday to hand over some Russian security contractors detained on terrorism charges who also are accused of fighting alongside Russian-backed separatists in eastern Ukraine.

"I hope that all those suspected in terrorist activities on Ukrainian territory will be handed over to us for prosecution in accordance with the existing international norms," Zelenskiy told Lukashenko, according to a readout of a phone call between the two leaders released by the Ukrainian president's office.

Belarusian authorities detained 33 fighters belonging to the notorious Russian mercenary organization, Wagner Group, last week and accused them of plotting terror attacks in advance of the presidential election in Belarus this weekend.

Officials in Kyiv said Friday they would ask Belarus to transfer 28 of the detainees, nine of whom also have Ukrainian citizenship. In Ukraine, they would face a criminal probe on the charges of involvement in a terrorist group for fighting on the side of the rebels in eastern Ukraine, the Prosecutor General's office said.

The government in Minsk claimed the detained contractors worked for the Wagner Group – a private military firm linked to Yevgeny Prigozhin, a Russian businessman who was indicted in the U.S. for meddling in the 2016 U.S. presidential election.

Wagner has allegedly deployed hundreds of military contractors to eastern Ukraine, Libya and Syria.

In July, U.S. Africa Command accused the Wagner Group of "complicating Libyan cease-fire efforts" by placing mines and other explosive devices in and around Tripoli. It included photos of what appeared to be booby-traps and improvised mines that it said were placed by the Wagner Group.

"The Russian-state sponsored Wagner Group is demonstrating a total disregard for the safety and security of Libyans," said Africa Command director of operations Maj. Gen. Bradford Gering.

Russia, mainly through the Wagner Group, as well as the United Arab Emirates (UAE) and Egypt have backed putschist Gen. Khalifa Haftar in his fight to seize power from the United Nations-recognized Government of National Accord (GNA) in Libya.