More than two years into a second war with separatist rebels in Chechnya, Russian forces are coming under increasing attack from rebel fighters there. At least ten Russian servicemen have been killed in just one 24-hour period this week.
Russian military officials say the troops died in a wave of attacks through the day Friday, as rebels fired on Russian checkpoints and vehicles.
In one incident, three soldiers were killed and eight were wounded when Chechen fighters set off a remote-controlled land mine near a Russian personnel carrier.
Officials say that more than 80 incidents have been reported in the past week.
In response, Russian troops have stepped up security patrols and have surrounded several villages for house-to-house searches.
President Vladimir Putin and other Russian leaders have long maintained that the war in the Caucasus mountain region is "over." Yet the repeated rebel attacks demonstrate that Chechens remain capable of exacting a terrible toll on the Russian forces.
Russian troops invaded Chechnya in October of 1999 to suppress the rebels' drive for total independence from Russia.
It was Moscow's second war against Chechnya. An earlier two-year conflict ended in 1996 with a tentative peace agreement. In the present war, the Chechens may have stepped up their attacks to mark the anniversary of the first major Russian offensive in the region, on New Year's Eve in 1994.
President Putin has come under pressure from human rights groups and international leaders over Chechnya.
In an interview with Russian media on Friday the U.S. ambassador in Moscow, Alexander Vershbow, said Russia should seek a negotiated end to the war in Chechnya.
Last month Russian and Chechen officials did meet, indicating the two sides may try to seek a political solution. However, the talks were inconclusive and no new meeting has been scheduled.