Heavy shelling overnight in the Georgian breakaway province of South Ossetia wounded at least 18 people, officials said Thursday.
The attacks in the provincial capital, Tskhinvali, and nearby areas came from Georgian-controlled territory and included heavy artillery and mortar shelling, South Ossetia's separatist government spokeswoman Irina Gagloyeva said.
Georgia's Interior Ministry said South Ossetian separatist forces started firing on Georgian troops in the area and they had to retaliate.
Most of South Ossetia, which is roughly 1.5 times the size of Luxembourg, has been under the control of an internationally unrecognized separatist government since the end of a war in the early 1990s. Georgian forces hold several swaths of it.
Tensions in the region have soared recently, stoking fears of full-scale war. Georgian and South Ossetian officials were scheduled to meet Thursday to try to find resolution, but Gagloyeva said that the meeting was off because of the Georgian shelling.
Georgia's Foreign Ministry said that South Ossetian authorities started firing in order to thwart the talks.
Eduard Kokoity, South Ossetia's separatist president, warned in comments broadcast by Russia's NTV television that the province's military would move to drive Georgian forces out of their firing positions near Tskhinvali if the shelling continues.
Russia has close ties with South Ossetia's separatist government and with a similar regime in Abkhazia, another Georgian breakaway province. Russia has granted passports to most of their residents, and Tbilisi accuses Russian peacekeeping forces in both regions of supporting the separatists.
An outbreak of open war in either region could prompt Russia to send in more forces under the claim of protecting its citizens.
Russia's Foreign Ministry already has warned earlier this week that Moscow "will not be able to let itself remain indifferent" in case of escalation of fighting in South Ossetia.
Russia sent warplanes to circle over South Ossetia last month while U.S. Secretary of State Condoleezza Rice was visiting the nearby Georgian capital; Russian officials said the planes were sent up to try to deter alleged Georgian plans to mount on offensive on South Ossetia.
Georgian officials have claimed Russia is the instigator of the recent fighting.
Relations between Tbilisi and Moscow have long been uneasy, but worsened notably this year amid Georgia's push to join NATO and Russia's dispatch of additional peacekeeper forces to Abkhazia.