MOSCOW (AFP) -- Up to 15,000 Russian soldiers have been sent to Ukraine over the past two months, and at least several hundred have apparently died in combat there, rights groups exposing army abuses told AFP on Monday.
Moscow denies that it has deployed regular troops to Ukraine to prop up separatists battling Kiev forces, but multiple indications have emerged over the past weeks that Russian soldiers are on the ground in Ukraine.
Valentina Melnikova, head of the Committee of Soldiers' Mothers, the top organisation representing the families of military servicemen, said that some 7,000-8,000 Russian troops are believed to be in Ukraine at present.
Citing her own estimates, she added that between 10,000 and 15,000 troops had been deployed to Ukraine over the past two months.
"Unfortunately, I am convinced I am right," she told AFP, saying her estimates are based on information from families whose husbands and sons have been sent on drills but then have gone incommunicado.
"Military commanders are conducting a secret special operation," said Melnikova, who is a member of the defence ministry's public council.
Rights groups say Russian authorities have imposed a virtual blackout on any information about the deployment of servicemen.
The Committee of Soldiers' Mothers and Citizen and Army, another rights group representing servicemen, said they don't have any officially confirmed casualty lists so far.
But the rights campaigners, citing information from relatives and servicemen, said that at least 200 servicemen might have died in Ukraine.
Sergei Krivenko, head of Citizen and the Army, and Ella Polyakova, head of Soldiers' Mothers in Saint Petersburg, said that some 100 soldiers from the 18th infantry brigade based in Chechnya are believed to have died in Ukraine.
"Authorities should say why soldiers are dying on the territory of another state and why they are keeping silent," said Polyakova, who is also a member of President Vladimir Putin's advisory council on human rights.
Separately, a Russian opposition lawmaker, Lev Shlosberg, probing Russian soldiers' presence in Ukraine, told AFP on Saturday that some 100 paratroopers based in the northwestern town of Pskov had died in the ex-Soviet country.
Lyudmila Bogatenkova, head of the Soldiers' Mothers group in the southern Stavropol region, added: "A large number of people are dying."
She said a hospital in the town of Rostov, close to the Ukrainian border, was overflowing with the wounded.
NATO has said that "over 1,000 Russian troops" are in Ukraine.