Russian military forces are carrying out “logistical exercises” in and around the Crimean Peninsula, the Ukrainian Black Sea region that Russia annexed in 2014.
Russia’s state RIA-Novosti agency announced the August 18 drills, noting only that land and naval forces are participating.
Tensions have been high in the region since Moscow earlier this month accused Ukraine of plotting “sabotage” attacks in Crimea. Kiev denies any such plots.
Recent weeks have also seen a noticeable increase in shelling and other violence in eastern Ukraine, where Kiev is battling against Russia-back separatists.
Ukrainian President Petro Poroshenko on August 17 warned that he does not rule out “a full-scale Russian invasion” and said that if the situation in the east and around Crimea continues to deteriorate, “we will have to impose martial law and order mobilization.”
Meanwhile, three troops have been killed and six wounded in eastern Ukraine in the most recent day of fighting, the Ukrainian president’s office said Thursday.
Fighting between government forces and separatists rebels has recently intensified despite a 2015 truce. More than 9,500 people have been killed in the conflict so far.
In the past 24 hours, separatists have shelled government positions twice as much as the day before, said Olexander Motuzyanyk, the Ukrainian presidential envoy for the operation in the east.
President Petro Poroshenko warned of a further flare-up of hostilities in the east and said that martial law could be imposed if the fighting gets worse.
“In case the situation in the east and in Crimea flares up, we will have to introduce martial law and declare a mobilization,” Poroshenko said in comments carried by the Interfax news agency.
Separatist officials in the rebel stronghold of Donetsk also reported heavy shelling of their positions in Donetsk and Horlivka Wednesday night, where the shelling cut electricity supply to hundreds of homes and a coal mine.