MOSCOW (AP) -- The last time Valeria Sokolova saw her husband, the 25-year-old paratrooper told her that he and his fellow soldiers were heading for military exercises in southern Russia, near the Ukrainian border.
"He was vague in a way that was very unusual, and it was hard for all of them to say goodbye," Sokolova told The Associated Press, recounting their conversation from earlier this month.
On Monday, 10 men from his division were captured in eastern Ukraine amid fighting between pro-Moscow separatists and Ukrainian troops. At least two others from the division were killed and an unspecified number were wounded.
Sokolova, the mother of a 6-year-old boy, does not know the fate of her husband, and she said Russian military officials have released no information about the servicemen. She fears for his safety.
Similar questions are being raised by families of other Russian servicemen about unexplained deaths and missing or captured soldiers who are said to be on military exercises. The answers could undermine public support for President Vladimir Putin and his policies in Ukraine.
The government has released little information about those killed while fighting with the rebels -- a policy that some have compared to one used during the Soviet intervention in Afghanistan in the 1980s. This secrecy may become more difficult to maintain if the death toll grows.
Sokolova, who declined to identify her husband further because she worries it could have consequences for him, said she and other army wives converged on the local garrison to demand answers.
"Only through each other did we find out the number of killed, wounded," she told the AP by telephone from Kostroma, a city 350 kilometers (210 miles) north of Moscow.
Russian officials, including Putin, have said the captured paratroopers had gotten lost and wandered over the border by mistake.
The news added to the growing evidence that Russia -- despite its denials -- is sending troops and weapons to fight alongside the separatists.
On Thursday, Ukraine accused Russia of sending tanks, armored vehicles and troops onto its soil. NATO said at least 1,000 Russian troops are in Ukraine and released what it said were satellite photos of Russian artillery units moving in last week.
Rebel leader Alexander Zakharchenko said up to 4,000 Russians have fought on the separatist side since the conflict began in April, including soldiers, but he said they were on leave and fighting voluntarily.
Two other cases involving the deaths of Russian troops have recently come to light.
This week, the presidential human rights commission published an open letter online demanding an investigation into the deaths this month of nine members of a motorized infantry brigade also sent to the southern Rostov region for military exercises.
The request to look into the deaths came from the Committee of Soldiers' Mothers, a highly respected non-governmental organization with a long history of working to defend the rights of soldiers. Within days, however, the commission's letter appeared to have been removed from its website.
In the northwestern region of Pskov, home of a major airborne division, the deaths of two paratroopers appear to have been suppressed. The names of the dead have been removed from fresh graves in a cemetery visited by local journalists, who were threatened or chased away by thugs. Relatives of dead or missing paratroopers reportedly have been warned not to talk to the media.
"This is the same old Soviet behavior," said Valentina Melnikova, the Moscow-based director of the Committee of Soldiers' Mothers.
"It reminds me of the secret burials of soldiers during the first half of the Afghan war," she said, referring to 1979-89 Soviet occupation of Afghanistan. "When they sent bodies back, they didn't give any information about where he had died and didn't allow people to write on his tombstone that he was a soldier."
Melnikova also said that in previous conflicts, such as the early stages of the war against separatists in Chechnya in the 1990s, many soldiers who were killed or captured on Chechen soil were listed on army rosters as having been on leave.
In recent days, Melnikova said she has received multiple reports from divisions where soldiers have been intimidated into signing up as contract troops and then whisked across the border.
"According to our military laws, they are supposed to be given a month's leave before their contract work starts," she said. "But they aren't given the leave; they're sent straight across the border."
Sokolova, the wife of the missing Kostroma paratrooper, was at home Tuesday when another soldier's wife called with the news that the 10 men in their husbands' division had been captured by Ukrainian troops.